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C#中的发票处理；：使用 .NET 生成、提取和自动处理 PDF 发票。

Curtis Chau
Curtis Chau
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C# .NET 中的发票处理。IronPDF for NET涵盖了整个文档生命周期：从HTML模板生成专业的PDF发票，符合ZUGFeRD和Factur-X电子发票标准，使用文本解析和AI驱动的处理从收到的发票中提取结构化数据，以及构建与QuickBooks、Xero和SAP等会计系统集成的批量自动化管道。

as-heading:2（TL;DR：快速入门指南）

本教程涵盖在 C# .NET 中生成、提取和自动化 PDF 发票，包括电子发票合规性、人工智能驱动的解析和会计系统集成。

  • 适用对象：构建发票模块、应付账款自动化或电子发票合规性的 .NET 开发人员。
  • 您将构建的内容：带有细列项目和税额计算的 HTML 模板发票生成、用于付款链接的 QR 代码、符合 ZUGFeRD/Factur-X 标准的 PDF/A-3 输出、使用 regex 的文本提取、人工智能驱动的发票解析以及与会计系统集成的批量处理。
  • 运行环境： .NET 10、.NET 8 LTS、.NET Framework 4.6.2+ 和 .NET Standard 2.0。不依赖外部服务。
  • 何时使用此方法：当您需要生成发票 PDF、满足欧盟电子发票要求或从供应商发票中提取数据用于应付账款时。
  • 为什么它在技术上很重要： IronPDF 可将 HTML 精确地渲染为 PDF，支持嵌入 XML 的 PDF/A-3，并提供文本提取 API，可与 regex 或 AI 配对，将非结构化发票转化为结构化数据。

只需几行代码，即可生成您的第一份 PDF 发票：

Nuget Icon立即开始使用 NuGet 创建 PDF 文件：

  1. 使用 NuGet 包管理器安装 IronPDF

    PM > Install-Package IronPdf

  2. 复制并运行这段代码。

    var renderer = new IronPdf.ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf("<h1>Invoice #1001</h1><p>Total: $500.00</p>");
pdf.SaveAs("invoice.pdf");

  3. 部署到您的生产环境中进行测试

    立即开始在您的项目中使用 IronPDF，免费试用！
    arrow pointer

购买或注册 IronPDF 30 天试用版后，请在应用程序的开头添加许可证密钥。

IronPdf.License.LicenseKey = "KEY";
IronPdf.License.LicenseKey = "KEY";
Imports IronPdf

IronPdf.License.LicenseKey = "KEY"
$vbLabelText   $csharpLabel

今天在您的项目中使用 IronPDF，免费试用。

第一步：
green arrow pointer
NuGet 使用 NuGet 安装

PM >  Install-Package IronPdf

在 IronPDF 上查看 NuGet 快速安装。超过 1000 万次下载，它正以 C# 改变 PDF 开发。 您也可以下载 DLL 或 Windows 安装程序。

as-heading:2（目录）

NuGet 使用 NuGet 安装

PM >  Install-Package IronPdf

在 IronPDF 上查看 NuGet 快速安装。超过 1000 万次下载，它正以 C# 改变 PDF 开发。 您也可以下载 DLL 或 Windows 安装程序。

什么是发票生命周期，为什么 PDF 仍是标准？

在深入研究代码之前，了解发票在现代业务系统中的整个流程会有所帮助。 发票的生命周期包括五个不同的阶段：生成、分发、接收、数据提取和会计整合。

发票流程从生成开始。 某企业创建了一张发票，其中包括细列项目、定价、税额计算、付款条件和品牌。 发票需要看起来很专业，并符合所有法律要求。 接下来是分发，即通过电子邮件、客户门户网站或传统邮件将发票发送给客户。 当客户收到文件后，应付账款团队会捕获文件并准备处理。 数据提取可从发票中提取关键信息，如供应商详情、细列项目、总额和到期日，以便与采购订单进行核对和匹配。 最后，会计集成将这些数据转移到 QuickBooks、Xero 或 SAP 等财务系统中，以便付款和保存记录。

为什么 PDF 这么多年来仍然是使用最广泛的格式？ 这归结为一个独特的优势组合。 无论您使用何种设备或操作系统，PDF 都能保持发票格式的一致性。 无论别人是在 Windows、Mac 还是手机上打开您的发票，它看起来都与您设计的一模一样。 PDF 也很难被误改，因此比 Word 或 Excel 等格式更能保护文档的完整性。 您可以添加数字签名以确保真实性，并使用加密技术以确保安全性。 最重要的是，PDF 已成为一种通用标准，每个业务系统都能识别和支持。

当然，这也是一项挑战。 PDF 的制作目的是方便人们阅读，而不是方便计算机处理。 PDF 不是以结构化数据存储信息，而是根据文本、线条、形状和图像在页面上出现的位置来保存它们。 这就是 IronPDF 这样的工具非常有用的原因，它们使得将人类友好的文档转化为软件可以使用的数据成为可能。

如何在 C# 中生成专业的 PDF 发票;

以编程方式生成发票需要将结构化数据（如客户信息、细列项目和计算结果）转换为精美的 PDF 文档。 IronPdf 利用 HTML 和 CSS 这些大多数开发人员都已熟知的技术，使翻译工作变得简单明了。

在本教程中，我们将介绍您在现实世界中可能遇到的情况。 您还可以在下载下面显示的项目。

如何构建发票 HTML 模板

IronPdf 生成发票的基础是 HTML。 与其与低级 PDF 绘图命令搏斗，不如使用标准 HTML 和 CSS 设计发票，然后让 IronPDF 基于 Chrome 浏览器的渲染引擎将其转换为像素完美的 PDF。

下面是一个基本的发票模板，展示了这种方法：

:path=/static-assets/pdf/content-code-examples/tutorials/csharp-invoice-processing/basic-invoice-template.cs
using IronPdf;

// Define the HTML template for a basic invoice
// Uses inline CSS for styling headers, tables, and totals
string invoiceHtml = @"
<!DOCTYPE html>
<html>
<head>
    <style>
        body { font-family: Arial, sans-serif; padding: 40px; }
        .header { text-align: right; margin-bottom: 40px; }
        .company-name { font-size: 24px; font-weight: bold; color: #333; }
        .invoice-title { font-size: 32px; margin: 20px 0; }
        .bill-to { margin: 20px 0; }
        table { width: 100%; border-collapse: collapse; margin: 20px 0; }
        th { background-color: #2A95D5; color: white; padding: 10px; text-align: left; }
        td { padding: 10px; border-bottom: 1px solid #ddd; }
        .total { text-align: right; font-size: 20px; font-weight: bold; margin-top: 20px; }
    </style>
</head>
<body>
    <div class='header'>
        <div class='company-name'>Your Company Name</div>
        <div>123 Business Street</div>
        <div>City, State 12345</div>
    </div>

    <div class='invoice-title'>INVOICE</div>

    <div class='bill-to'>
        <strong>Bill To:</strong><br>
        Customer Name<br>
        456 Customer Avenue<br>
        City, State 67890
    </div>

    <table>
        <tr>
            <th>Description</th>
            <th>Quantity</th>
            <th>Price</th>
            <th>Total</th>
        </tr>
        <tr>
            <td>Web Development Services</td>
            <td>10 hours</td>
            <td>$100.00</td>
            <td>$1,000.00</td>
        </tr>
        <tr>
            <td>Consulting</td>
            <td>5 hours</td>
            <td>$150.00</td>
            <td>$750.00</td>
        </tr>
    </table>

    <div class='total'>Total: $1,750.00</div>
</body>
</html>";

// Initialize the Chrome-based PDF renderer
var renderer = new ChromePdfRenderer();

// Convert the HTML string to a PDF document
var pdf = renderer.RenderHtmlAsPdf(invoiceHtml);

// Save the generated PDF to disk
pdf.SaveAs("basic-invoice.pdf");

Imports IronPdf

' Define the HTML template for a basic invoice
' Uses inline CSS for styling headers, tables, and totals
Dim invoiceHtml As String = "
<!DOCTYPE html>
<html>
<head>
    <style>
        body { font-family: Arial, sans-serif; padding: 40px; }
        .header { text-align: right; margin-bottom: 40px; }
        .company-name { font-size: 24px; font-weight: bold; color: #333; }
        .invoice-title { font-size: 32px; margin: 20px 0; }
        .bill-to { margin: 20px 0; }
        table { width: 100%; border-collapse: collapse; margin: 20px 0; }
        th { background-color: #2A95D5; color: white; padding: 10px; text-align: left; }
        td { padding: 10px; border-bottom: 1px solid #ddd; }
        .total { text-align: right; font-size: 20px; font-weight: bold; margin-top: 20px; }
    </style>
</head>
<body>
    <div class='header'>
        <div class='company-name'>Your Company Name</div>
        <div>123 Business Street</div>
        <div>City, State 12345</div>
    </div>

    <div class='invoice-title'>INVOICE</div>

    <div class='bill-to'>
        <strong>Bill To:</strong><br>
        Customer Name<br>
        456 Customer Avenue<br>
        City, State 67890
    </div>

    <table>
        <tr>
            <th>Description</th>
            <th>Quantity</th>
            <th>Price</th>
            <th>Total</th>
        </tr>
        <tr>
            <td>Web Development Services</td>
            <td>10 hours</td>
            <td>$100.00</td>
            <td>$1,000.00</td>
        </tr>
        <tr>
            <td>Consulting</td>
            <td>5 hours</td>
            <td>$150.00</td>
            <td>$750.00</td>
        </tr>
    </table>

    <div class='total'>Total: $1,750.00</div>
</body>
</html>"

' Initialize the Chrome-based PDF renderer
Dim renderer As New ChromePdfRenderer()

' Convert the HTML string to a PDF document
Dim pdf = renderer.RenderHtmlAsPdf(invoiceHtml)

' Save the generated PDF to disk
pdf.SaveAs("basic-invoice.pdf")
$vbLabelText   $csharpLabel

输出示例

这种方法具有极大的灵活性。 任何能在 Chrome 中使用的 CSS 都能在您的 PDF 中使用，包括 flexbox、网格布局和自定义字体等现代功能。 您甚至可以通过引用 URL 或本地文件路径来使用外部样式表和图片。

如何添加动态行项目并计算总数

真实发票很少有静态内容。 您需要从数据库中填充细列项目、计算小计、应用税率并格式化货币值。 下面的示例演示了动态发票生成的生产就绪模式：

using IronPdf;
using System;
using System.Collections.Generic;
using System.Linq;

// Represents a single line item on an invoice
public class InvoiceLineItem
{
    public string Description { get; set; }
    public decimal Quantity { get; set; }
    public decimal UnitPrice { get; set; }

    // Auto-calculates line total from quantity and unit price
    public decimal Total => Quantity * UnitPrice;
}

// Represents a complete invoice with customer details and line items
public class Invoice
{
    public string InvoiceNumber { get; set; }
    public DateTime InvoiceDate { get; set; }
    public string CustomerName { get; set; }
    public string CustomerAddress { get; set; }
    public List<InvoiceLineItem> LineItems { get; set; }

    // Computed properties for invoice totals
    public decimal Subtotal => LineItems.Sum(item => item.Total);
    public decimal TaxRate { get; set; } = 0.08m;  // Default 8% tax rate
    public decimal Tax => Subtotal * TaxRate;
    public decimal Total => Subtotal + Tax;
}

// Generates PDF invoices from Invoice objects using HTML templates
public class InvoiceGenerator
{
    public PdfDocument GenerateInvoice(Invoice invoice)
    {
        // Build HTML table rows dynamically from line items
        string lineItemsHtml = string.Join("", invoice.LineItems.Select(item => $@"
            <tr>
                <td>{item.Description}</td>
                <td>{item.Quantity}</td>
                <td>${item.UnitPrice:F2}</td>
                <td>${item.Total:F2}</td>
            </tr>
        "));

        // Build the complete HTML invoice using string interpolation
        // All invoice data is injected into the template dynamically
        string invoiceHtml = $@"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        .header {{ text-align: right; margin-bottom: 40px; }}
        .company-name {{ font-size: 24px; font-weight: bold; color: #333; }}
        .invoice-details {{ margin: 20px 0; }}
        table {{ width: 100%; border-collapse: collapse; margin: 20px 0; }}
        th {{ background-color: #2A95D5; color: white; padding: 10px; text-align: left; }}
        td {{ padding: 10px; border-bottom: 1px solid #ddd; }}
        .totals {{ text-align: right; margin-top: 20px; }}
        .totals div {{ margin: 5px 0; }}
        .grand-total {{ font-size: 20px; font-weight: bold; color: #2A95D5; }}
    </style>
</head>
<body>
    <div class='header'>
        <div class='company-name'>Your Company Name</div>
    </div>

    <h1>INVOICE</h1>

    <div class='invoice-details'>
        <strong>Invoice Number:</strong> {invoice.InvoiceNumber}<br>
        <strong>Date:</strong> {invoice.InvoiceDate:MMM dd, yyyy}<br>
        <strong>Bill To:</strong> {invoice.CustomerName}<br>
        {invoice.CustomerAddress}
    </div>

    <table>
        <tr>
            <th>Description</th>
            <th>Quantity</th>
            <th>Unit Price</th>
            <th>Total</th>
        </tr>
        {lineItemsHtml}
    </table>

    <div class='totals'>
        <div>Subtotal: ${invoice.Subtotal:F2}</div>
        <div>Tax ({invoice.TaxRate:P0}): ${invoice.Tax:F2}</div>
        <div class='grand-total'>Total: ${invoice.Total:F2}</div>
    </div>
</body>
</html>";

        // Render HTML to PDF and return the document
        var renderer = new ChromePdfRenderer();
        return renderer.RenderHtmlAsPdf(invoiceHtml);
    }
}
using IronPdf;
using System;
using System.Collections.Generic;
using System.Linq;

// Represents a single line item on an invoice
public class InvoiceLineItem
{
    public string Description { get; set; }
    public decimal Quantity { get; set; }
    public decimal UnitPrice { get; set; }

    // Auto-calculates line total from quantity and unit price
    public decimal Total => Quantity * UnitPrice;
}

// Represents a complete invoice with customer details and line items
public class Invoice
{
    public string InvoiceNumber { get; set; }
    public DateTime InvoiceDate { get; set; }
    public string CustomerName { get; set; }
    public string CustomerAddress { get; set; }
    public List<InvoiceLineItem> LineItems { get; set; }

    // Computed properties for invoice totals
    public decimal Subtotal => LineItems.Sum(item => item.Total);
    public decimal TaxRate { get; set; } = 0.08m;  // Default 8% tax rate
    public decimal Tax => Subtotal * TaxRate;
    public decimal Total => Subtotal + Tax;
}

// Generates PDF invoices from Invoice objects using HTML templates
public class InvoiceGenerator
{
    public PdfDocument GenerateInvoice(Invoice invoice)
    {
        // Build HTML table rows dynamically from line items
        string lineItemsHtml = string.Join("", invoice.LineItems.Select(item => $@"
            <tr>
                <td>{item.Description}</td>
                <td>{item.Quantity}</td>
                <td>${item.UnitPrice:F2}</td>
                <td>${item.Total:F2}</td>
            </tr>
        "));

        // Build the complete HTML invoice using string interpolation
        // All invoice data is injected into the template dynamically
        string invoiceHtml = $@"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        .header {{ text-align: right; margin-bottom: 40px; }}
        .company-name {{ font-size: 24px; font-weight: bold; color: #333; }}
        .invoice-details {{ margin: 20px 0; }}
        table {{ width: 100%; border-collapse: collapse; margin: 20px 0; }}
        th {{ background-color: #2A95D5; color: white; padding: 10px; text-align: left; }}
        td {{ padding: 10px; border-bottom: 1px solid #ddd; }}
        .totals {{ text-align: right; margin-top: 20px; }}
        .totals div {{ margin: 5px 0; }}
        .grand-total {{ font-size: 20px; font-weight: bold; color: #2A95D5; }}
    </style>
</head>
<body>
    <div class='header'>
        <div class='company-name'>Your Company Name</div>
    </div>

    <h1>INVOICE</h1>

    <div class='invoice-details'>
        <strong>Invoice Number:</strong> {invoice.InvoiceNumber}<br>
        <strong>Date:</strong> {invoice.InvoiceDate:MMM dd, yyyy}<br>
        <strong>Bill To:</strong> {invoice.CustomerName}<br>
        {invoice.CustomerAddress}
    </div>

    <table>
        <tr>
            <th>Description</th>
            <th>Quantity</th>
            <th>Unit Price</th>
            <th>Total</th>
        </tr>
        {lineItemsHtml}
    </table>

    <div class='totals'>
        <div>Subtotal: ${invoice.Subtotal:F2}</div>
        <div>Tax ({invoice.TaxRate:P0}): ${invoice.Tax:F2}</div>
        <div class='grand-total'>Total: ${invoice.Total:F2}</div>
    </div>
</body>
</html>";

        // Render HTML to PDF and return the document
        var renderer = new ChromePdfRenderer();
        return renderer.RenderHtmlAsPdf(invoiceHtml);
    }
}
Imports IronPdf
Imports System
Imports System.Collections.Generic
Imports System.Linq

' Represents a single line item on an invoice
Public Class InvoiceLineItem
    Public Property Description As String
    Public Property Quantity As Decimal
    Public Property UnitPrice As Decimal

    ' Auto-calculates line total from quantity and unit price
    Public ReadOnly Property Total As Decimal
        Get
            Return Quantity * UnitPrice
        End Get
    End Property
End Class

' Represents a complete invoice with customer details and line items
Public Class Invoice
    Public Property InvoiceNumber As String
    Public Property InvoiceDate As DateTime
    Public Property CustomerName As String
    Public Property CustomerAddress As String
    Public Property LineItems As List(Of InvoiceLineItem)

    ' Computed properties for invoice totals
    Public ReadOnly Property Subtotal As Decimal
        Get
            Return LineItems.Sum(Function(item) item.Total)
        End Get
    End Property

    Public Property TaxRate As Decimal = 0.08D ' Default 8% tax rate

    Public ReadOnly Property Tax As Decimal
        Get
            Return Subtotal * TaxRate
        End Get
    End Property

    Public ReadOnly Property Total As Decimal
        Get
            Return Subtotal + Tax
        End Get
    End Property
End Class

' Generates PDF invoices from Invoice objects using HTML templates
Public Class InvoiceGenerator
    Public Function GenerateInvoice(invoice As Invoice) As PdfDocument
        ' Build HTML table rows dynamically from line items
        Dim lineItemsHtml As String = String.Join("", invoice.LineItems.Select(Function(item) $"
            <tr>
                <td>{item.Description}</td>
                <td>{item.Quantity}</td>
                <td>${item.UnitPrice:F2}</td>
                <td>${item.Total:F2}</td>
            </tr>
        "))

        ' Build the complete HTML invoice using string interpolation
        ' All invoice data is injected into the template dynamically
        Dim invoiceHtml As String = $"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        .header {{ text-align: right; margin-bottom: 40px; }}
        .company-name {{ font-size: 24px; font-weight: bold; color: #333; }}
        .invoice-details {{ margin: 20px 0; }}
        table {{ width: 100%; border-collapse: collapse; margin: 20px 0; }}
        th {{ background-color: #2A95D5; color: white; padding: 10px; text-align: left; }}
        td {{ padding: 10px; border-bottom: 1px solid #ddd; }}
        .totals {{ text-align: right; margin-top: 20px; }}
        .totals div {{ margin: 5px 0; }}
        .grand-total {{ font-size: 20px; font-weight: bold; color: #2A95D5; }}
    </style>
</head>
<body>
    <div class='header'>
        <div class='company-name'>Your Company Name</div>
    </div>

    <h1>INVOICE</h1>

    <div class='invoice-details'>
        <strong>Invoice Number:</strong> {invoice.InvoiceNumber}<br>
        <strong>Date:</strong> {invoice.InvoiceDate:MMM dd, yyyy}<br>
        <strong>Bill To:</strong> {invoice.CustomerName}<br>
        {invoice.CustomerAddress}
    </div>

    <table>
        <tr>
            <th>Description</th>
            <th>Quantity</th>
            <th>Unit Price</th>
            <th>Total</th>
        </tr>
        {lineItemsHtml}
    </table>

    <div class='totals'>
        <div>Subtotal: ${invoice.Subtotal:F2}</div>
        <div>Tax ({invoice.TaxRate:P0}): ${invoice.Tax:F2}</div>
        <div class='grand-total'>Total: ${invoice.Total:F2}</div>
    </div>
</body>
</html>"

        ' Render HTML to PDF and return the document
        Dim renderer As New ChromePdfRenderer()
        Return renderer.RenderHtmlAsPdf(invoiceHtml)
    End Function
End Class
$vbLabelText   $csharpLabel

输出示例

Invoice 类封装了所有发票数据，并具有小计、税金和总额的计算属性。 生成器使用字符串插值将这些数据转换为 HTML，然后渲染为 PDF。 这种分工使代码具有可维护性和可测试性。

如何在发票上添加公司品牌和水印

专业发票需要徽标等品牌元素，有时还需要水印来显示付款状态。 IronPDF 既支持 HTML 中的嵌入式图像，也支持渲染后的程序化水印。

:path=/static-assets/pdf/content-code-examples/tutorials/csharp-invoice-processing/branding-watermarks.cs
using IronPdf;
using IronPdf;

var renderer = new ChromePdfRenderer();

// Invoice HTML template with company logo embedded via URL
// Logo can also be Base64-encoded or a local file path
string htmlWithLogo = @"
<!DOCTYPE html>
<html>
<head>
    <style>
        body { font-family: Arial, sans-serif; padding: 40px; }
        .logo { width: 200px; margin-bottom: 20px; }
    </style>
</head>
<body>
    <div style='text-align: center;'>
        <img src='https://yourcompany.com/logo.png' alt='Company Logo' class='logo' />
    </div>
    <h1>INVOICE</h1>
    <p><strong>Invoice Number:</strong> INV-2024-001</p>
    <p><strong>Total:</strong> $1,250.00</p>
</body>
</html>";

// Render the HTML to PDF
var pdf = renderer.RenderHtmlAsPdf(htmlWithLogo);

// Apply a diagonal "UNPAID" watermark to mark invoice status
// 30% opacity keeps the content readable while the watermark is visible
pdf.ApplyWatermark("<h1 style='color: red;'>UNPAID</h1>",
    opacity: 30,
    rotation: 45,
    verticalAlignment: IronPdf.Editing.VerticalAlignment.Middle);

pdf.SaveAs("invoice-with-watermark.pdf");

using IronPdf;
Imports IronPdf

Dim renderer As New ChromePdfRenderer()

' Invoice HTML template with company logo embedded via URL
' Logo can also be Base64-encoded or a local file path
Dim htmlWithLogo As String = "
<!DOCTYPE html>
<html>
<head>
    <style>
        body { font-family: Arial, sans-serif; padding: 40px; }
        .logo { width: 200px; margin-bottom: 20px; }
    </style>
</head>
<body>
    <div style='text-align: center;'>
        <img src='https://yourcompany.com/logo.png' alt='Company Logo' class='logo' />
    </div>
    <h1>INVOICE</h1>
    <p><strong>Invoice Number:</strong> INV-2024-001</p>
    <p><strong>Total:</strong> $1,250.00</p>
</body>
</html>"

' Render the HTML to PDF
Dim pdf = renderer.RenderHtmlAsPdf(htmlWithLogo)

' Apply a diagonal "UNPAID" watermark to mark invoice status
' 30% opacity keeps the content readable while the watermark is visible
pdf.ApplyWatermark("<h1 style='color: red;'>UNPAID</h1>",
                   opacity:=30,
                   rotation:=45,
                   verticalAlignment:=IronPdf.Editing.VerticalAlignment.Middle)

pdf.SaveAs("invoice-with-watermark.pdf")
$vbLabelText   $csharpLabel

输出示例

ApplyWatermark 方法接受 HTML 内容，使您可以完全控制水印的外观。 您可以调整不透明度、旋转和定位，以达到您所需要的效果。 这对于将发票标记为 "已付"、"草稿 "或 "取消 "而无需重新生成整个文档尤其有用。

如何为支付链接嵌入二维码

现代发票通常包含二维码，客户可以扫描二维码快速付款。 虽然 IronPDF 专注于 PDF 生成，但它可与 IronQR 无缝协作，用于创建条形码：

:path=/static-assets/pdf/content-code-examples/tutorials/csharp-invoice-processing/qr-code-payment.cs
using IronPdf;
using IronQr;
using IronSoftware.Drawing;

// Generates PDF invoices with embedded QR codes for quick mobile payment
public class InvoiceWithQRGenerator
{
    public void GenerateInvoiceWithQR(string invoiceNumber, decimal amount)
    {
        // Create a payment URL with invoice details as query parameters
        string paymentUrl = $"https://yourcompany.com/pay?invoice={invoiceNumber}&amount={amount}";

        // Generate QR code from the payment URL using IronQR
        QrCode qrCode = QrWriter.Write(paymentUrl);
        AnyBitmap qrImage = qrCode.Save();
        qrImage.SaveAs("payment-qr.png", AnyBitmap.ImageFormat.Png);

        // Build invoice HTML with the QR code image embedded
        // Customers can scan the QR to pay directly from their phone
        string invoiceHtml = $@"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        .payment-section {{ margin-top: 40px; text-align: center;
                           border-top: 2px solid #eee; padding-top: 20px; }}
        .qr-code {{ width: 150px; height: 150px; }}
    </style>
</head>
<body>
    <h1>INVOICE {invoiceNumber}</h1>
    <p><strong>Amount Due:</strong> ${amount:F2}</p>

    <div class='payment-section'>
        <p><strong>Scan to Pay Instantly:</strong></p>
        <img src='payment-qr.png' alt='Payment QR Code' class='qr-code' />
        <p style='font-size: 12px; color: #666;'>
            Or visit: {paymentUrl}
        </p>
    </div>
</body>
</html>";

        // Convert HTML to PDF and save
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf(invoiceHtml);
        pdf.SaveAs($"invoice-{invoiceNumber}.pdf");
    }
}

Imports IronPdf
Imports IronQr
Imports IronSoftware.Drawing

' Generates PDF invoices with embedded QR codes for quick mobile payment
Public Class InvoiceWithQRGenerator
    Public Sub GenerateInvoiceWithQR(invoiceNumber As String, amount As Decimal)
        ' Create a payment URL with invoice details as query parameters
        Dim paymentUrl As String = $"https://yourcompany.com/pay?invoice={invoiceNumber}&amount={amount}"

        ' Generate QR code from the payment URL using IronQR
        Dim qrCode As QrCode = QrWriter.Write(paymentUrl)
        Dim qrImage As AnyBitmap = qrCode.Save()
        qrImage.SaveAs("payment-qr.png", AnyBitmap.ImageFormat.Png)

        ' Build invoice HTML with the QR code image embedded
        ' Customers can scan the QR to pay directly from their phone
        Dim invoiceHtml As String = $"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        .payment-section {{ margin-top: 40px; text-align: center;
                           border-top: 2px solid #eee; padding-top: 20px; }}
        .qr-code {{ width: 150px; height: 150px; }}
    </style>
</head>
<body>
    <h1>INVOICE {invoiceNumber}</h1>
    <p><strong>Amount Due:</strong> ${amount:F2}</p>

    <div class='payment-section'>
        <p><strong>Scan to Pay Instantly:</strong></p>
        <img src='payment-qr.png' alt='Payment QR Code' class='qr-code' />
        <p style='font-size: 12px; color: #666;'>
            Or visit: {paymentUrl}
        </p>
    </div>
</body>
</html>"

        ' Convert HTML to PDF and save
        Dim renderer = New ChromePdfRenderer()
        Dim pdf = renderer.RenderHtmlAsPdf(invoiceHtml)
        pdf.SaveAs($"invoice-{invoiceNumber}.pdf")
    End Sub
End Class
$vbLabelText   $csharpLabel

输出示例

二维码可直接链接到支付页面，减少客户操作的摩擦，加快现金流。 该模式适用于任何支持基于 URL 的支付启动的支付提供商。

如何在 C# 中遵守 ZUGFeRD 和 Factur-X 电子发票标准；

在整个欧洲，电子发票正迅速成为强制性规定。 德国以 ZUGFeRD 领先，法国以 Factur-X 紧随其后。 这些标准在 PDF 发票中嵌入了机器可读的 XML 数据，实现了自动处理，同时保留了人类可读的文档。 对于在欧洲市场运营的企业来说，理解和实施这些标准越来越重要。

什么是 ZUGFeRD 及其工作原理？

ZUGFeRD（Zentraler User Guide des Forums elektronische Rechnung Deutschland）是德国电子发票标准，它将发票数据作为 XML 文件附件嵌入符合 PDF/A-3 标准的文档中。 嵌入式 XML 可自动提取数据，无需 OCR 或解析。

该标准定义了三个一致性级别，每个级别提供的数据结构逐步完善：

  • 基本：包含适合简单自动处理的核心发票数据
  • 舒适：添加详细信息，实现全自动发票处理
  • 扩展： 包括各行业复杂业务场景的全面数据

XML 遵循 UN/CEFACT 跨行业发票 (CII) 模式，该模式已成为欧洲电子发票标准化的基础。

什么是 Factur-X，它与 ZUGFeRD 有何不同？

Factur-X 是同一基础标准的法语实施版本。 ZUGFeRD 2.0 和 Factur-X 在技术上完全相同。 它们共享相同的 XML 架构和基于欧洲规范 EN 16931 的一致性配置文件。它们之间的区别纯粹是区域命名：根据 ZUGFeRD 规范创建的发票在 Factur-X 下有效，反之亦然。

如何在 PDF/A-3 发票中嵌入 XML 数据

IronPDF 提供创建合规电子发票所需的附件功能。 翻译过程包括生成 PDF 格式的发票，根据 CII 模式创建 XML 数据，并以正确的命名约定将 XML 作为附件嵌入：

using System;
using System.Xml.Linq;

// Generates ZUGFeRD-compliant invoices by embedding structured XML data
// ZUGFeRD allows automated processing while keeping a human-readable PDF
public class ZUGFeRDInvoiceGenerator
{
    public void GenerateZUGFeRDInvoice(Invoice invoice)
    {
        // First, create the visual PDF that humans will read
        var renderer = new ChromePdfRenderer();
        string invoiceHtml = BuildInvoiceHtml(invoice);
        var pdf = renderer.RenderHtmlAsPdf(invoiceHtml);

        // Define the UN/CEFACT namespaces required by the ZUGFeRD standard
        // These are mandatory for compliance with European e-invoicing regulations
        XNamespace rsm = "urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100";
        XNamespace ram = "urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:100";
        XNamespace udt = "urn:un:unece:uncefact:data:standard:UnqualifiedDataType:100";

        // Build the ZUGFeRD XML structure following the Cross-Industry Invoice schema
        var zugferdXml = new XDocument(
            new XDeclaration("1.0", "UTF-8", null),
            new XElement(rsm + "CrossIndustryInvoice",
                new XAttribute(XNamespace.Xmlns + "rsm", rsm.NamespaceName),
                new XAttribute(XNamespace.Xmlns + "ram", ram.NamespaceName),
                new XAttribute(XNamespace.Xmlns + "udt", udt.NamespaceName),

                // Document context identifies which e-invoicing guideline is being followed
                new XElement(rsm + "ExchangedDocumentContext",
                    new XElement(ram + "GuidelineSpecifiedDocumentContextParameter",
                        new XElement(ram + "ID", "urn:cen.eu:en16931:2017")
                    )
                ),

                // Core document identification: invoice number, type, and date
                new XElement(rsm + "ExchangedDocument",
                    new XElement(ram + "ID", invoice.InvoiceNumber),
                    new XElement(ram + "TypeCode", "380"), // 380 = Commercial Invoice per UN/CEFACT
                    new XElement(ram + "IssueDateTime",
                        new XElement(udt + "DateTimeString",
                            new XAttribute("format", "102"),
                            invoice.InvoiceDate.ToString("yyyyMMdd")
                        )
                    )
                ),

                // A complete implementation would include additional sections:
                // - Seller information (ram:SellerTradeParty)
                // - Buyer information (ram:BuyerTradeParty)
                // - Line items (ram:IncludedSupplyChainTradeLineItem)
                // - Payment terms (ram:SpecifiedTradePaymentTerms)
                // - Tax summaries (ram:ApplicableTradeTax)

                // Financial summary with all monetary totals
                new XElement(rsm + "SupplyChainTradeTransaction",
                    new XElement(ram + "ApplicableHeaderTradeSettlement",
                        new XElement(ram + "InvoiceCurrencyCode", "EUR"),
                        new XElement(ram + "SpecifiedTradeSettlementHeaderMonetarySummation",
                            new XElement(ram + "TaxBasisTotalAmount", invoice.Subtotal),
                            new XElement(ram + "TaxTotalAmount",
                                new XAttribute("currencyID", "EUR"),
                                invoice.Tax),
                            new XElement(ram + "GrandTotalAmount", invoice.Total),
                            new XElement(ram + "DuePayableAmount", invoice.Total)
                        )
                    )
                )
            )
        );

        // Save the XML to a temp file for embedding
        string xmlPath = $"zugferd-{invoice.InvoiceNumber}.xml";
        zugferdXml.Save(xmlPath);

        // Attach the XML to the PDF - filename must follow ZUGFeRD conventions
        pdf.Attachments.AddFile(xmlPath, "zugferd-invoice.xml", "ZUGFeRD Invoice Data");

        // Final PDF contains both visual invoice and machine-readable XML
        pdf.SaveAs($"invoice-{invoice.InvoiceNumber}-zugferd.pdf");
    }

    // Generates simple HTML for the visual portion of the invoice
    private string BuildInvoiceHtml(Invoice invoice)
    {
        return $@"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        h1 {{ color: #333; }}
        .zugferd-notice {{ 
            margin-top: 30px; padding: 10px; 
            background: #f0f0f0; font-size: 11px; 
        }}
    </style>
</head>
<body>
    <h1>RECHNUNG / INVOICE</h1>
    <p><strong>Rechnungsnummer:</strong> {invoice.InvoiceNumber}</p>
    <p><strong>Datum:</strong> {invoice.InvoiceDate:dd.MM.yyyy}</p>
    <p><strong>Betrag:</strong> €{invoice.Total:F2}</p>

    <div class='zugferd-notice'>
        This invoice contains embedded ZUGFeRD data for automated processing.
    </div>
</body>
</html>";
    }
}
using System;
using System.Xml.Linq;

// Generates ZUGFeRD-compliant invoices by embedding structured XML data
// ZUGFeRD allows automated processing while keeping a human-readable PDF
public class ZUGFeRDInvoiceGenerator
{
    public void GenerateZUGFeRDInvoice(Invoice invoice)
    {
        // First, create the visual PDF that humans will read
        var renderer = new ChromePdfRenderer();
        string invoiceHtml = BuildInvoiceHtml(invoice);
        var pdf = renderer.RenderHtmlAsPdf(invoiceHtml);

        // Define the UN/CEFACT namespaces required by the ZUGFeRD standard
        // These are mandatory for compliance with European e-invoicing regulations
        XNamespace rsm = "urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100";
        XNamespace ram = "urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:100";
        XNamespace udt = "urn:un:unece:uncefact:data:standard:UnqualifiedDataType:100";

        // Build the ZUGFeRD XML structure following the Cross-Industry Invoice schema
        var zugferdXml = new XDocument(
            new XDeclaration("1.0", "UTF-8", null),
            new XElement(rsm + "CrossIndustryInvoice",
                new XAttribute(XNamespace.Xmlns + "rsm", rsm.NamespaceName),
                new XAttribute(XNamespace.Xmlns + "ram", ram.NamespaceName),
                new XAttribute(XNamespace.Xmlns + "udt", udt.NamespaceName),

                // Document context identifies which e-invoicing guideline is being followed
                new XElement(rsm + "ExchangedDocumentContext",
                    new XElement(ram + "GuidelineSpecifiedDocumentContextParameter",
                        new XElement(ram + "ID", "urn:cen.eu:en16931:2017")
                    )
                ),

                // Core document identification: invoice number, type, and date
                new XElement(rsm + "ExchangedDocument",
                    new XElement(ram + "ID", invoice.InvoiceNumber),
                    new XElement(ram + "TypeCode", "380"), // 380 = Commercial Invoice per UN/CEFACT
                    new XElement(ram + "IssueDateTime",
                        new XElement(udt + "DateTimeString",
                            new XAttribute("format", "102"),
                            invoice.InvoiceDate.ToString("yyyyMMdd")
                        )
                    )
                ),

                // A complete implementation would include additional sections:
                // - Seller information (ram:SellerTradeParty)
                // - Buyer information (ram:BuyerTradeParty)
                // - Line items (ram:IncludedSupplyChainTradeLineItem)
                // - Payment terms (ram:SpecifiedTradePaymentTerms)
                // - Tax summaries (ram:ApplicableTradeTax)

                // Financial summary with all monetary totals
                new XElement(rsm + "SupplyChainTradeTransaction",
                    new XElement(ram + "ApplicableHeaderTradeSettlement",
                        new XElement(ram + "InvoiceCurrencyCode", "EUR"),
                        new XElement(ram + "SpecifiedTradeSettlementHeaderMonetarySummation",
                            new XElement(ram + "TaxBasisTotalAmount", invoice.Subtotal),
                            new XElement(ram + "TaxTotalAmount",
                                new XAttribute("currencyID", "EUR"),
                                invoice.Tax),
                            new XElement(ram + "GrandTotalAmount", invoice.Total),
                            new XElement(ram + "DuePayableAmount", invoice.Total)
                        )
                    )
                )
            )
        );

        // Save the XML to a temp file for embedding
        string xmlPath = $"zugferd-{invoice.InvoiceNumber}.xml";
        zugferdXml.Save(xmlPath);

        // Attach the XML to the PDF - filename must follow ZUGFeRD conventions
        pdf.Attachments.AddFile(xmlPath, "zugferd-invoice.xml", "ZUGFeRD Invoice Data");

        // Final PDF contains both visual invoice and machine-readable XML
        pdf.SaveAs($"invoice-{invoice.InvoiceNumber}-zugferd.pdf");
    }

    // Generates simple HTML for the visual portion of the invoice
    private string BuildInvoiceHtml(Invoice invoice)
    {
        return $@"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        h1 {{ color: #333; }}
        .zugferd-notice {{ 
            margin-top: 30px; padding: 10px; 
            background: #f0f0f0; font-size: 11px; 
        }}
    </style>
</head>
<body>
    <h1>RECHNUNG / INVOICE</h1>
    <p><strong>Rechnungsnummer:</strong> {invoice.InvoiceNumber}</p>
    <p><strong>Datum:</strong> {invoice.InvoiceDate:dd.MM.yyyy}</p>
    <p><strong>Betrag:</strong> €{invoice.Total:F2}</p>

    <div class='zugferd-notice'>
        This invoice contains embedded ZUGFeRD data for automated processing.
    </div>
</body>
</html>";
    }
}
Imports System
Imports System.Xml.Linq

' Generates ZUGFeRD-compliant invoices by embedding structured XML data
' ZUGFeRD allows automated processing while keeping a human-readable PDF
Public Class ZUGFeRDInvoiceGenerator
    Public Sub GenerateZUGFeRDInvoice(invoice As Invoice)
        ' First, create the visual PDF that humans will read
        Dim renderer = New ChromePdfRenderer()
        Dim invoiceHtml As String = BuildInvoiceHtml(invoice)
        Dim pdf = renderer.RenderHtmlAsPdf(invoiceHtml)

        ' Define the UN/CEFACT namespaces required by the ZUGFeRD standard
        ' These are mandatory for compliance with European e-invoicing regulations
        Dim rsm As XNamespace = "urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100"
        Dim ram As XNamespace = "urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:100"
        Dim udt As XNamespace = "urn:un:unece:uncefact:data:standard:UnqualifiedDataType:100"

        ' Build the ZUGFeRD XML structure following the Cross-Industry Invoice schema
        Dim zugferdXml = New XDocument(
            New XDeclaration("1.0", "UTF-8", Nothing),
            New XElement(rsm + "CrossIndustryInvoice",
                New XAttribute(XNamespace.Xmlns + "rsm", rsm.NamespaceName),
                New XAttribute(XNamespace.Xmlns + "ram", ram.NamespaceName),
                New XAttribute(XNamespace.Xmlns + "udt", udt.NamespaceName),

                ' Document context identifies which e-invoicing guideline is being followed
                New XElement(rsm + "ExchangedDocumentContext",
                    New XElement(ram + "GuidelineSpecifiedDocumentContextParameter",
                        New XElement(ram + "ID", "urn:cen.eu:en16931:2017")
                    )
                ),

                ' Core document identification: invoice number, type, and date
                New XElement(rsm + "ExchangedDocument",
                    New XElement(ram + "ID", invoice.InvoiceNumber),
                    New XElement(ram + "TypeCode", "380"), ' 380 = Commercial Invoice per UN/CEFACT
                    New XElement(ram + "IssueDateTime",
                        New XElement(udt + "DateTimeString",
                            New XAttribute("format", "102"),
                            invoice.InvoiceDate.ToString("yyyyMMdd")
                        )
                    )
                ),

                ' A complete implementation would include additional sections:
                ' - Seller information (ram:SellerTradeParty)
                ' - Buyer information (ram:BuyerTradeParty)
                ' - Line items (ram:IncludedSupplyChainTradeLineItem)
                ' - Payment terms (ram:SpecifiedTradePaymentTerms)
                ' - Tax summaries (ram:ApplicableTradeTax)

                ' Financial summary with all monetary totals
                New XElement(rsm + "SupplyChainTradeTransaction",
                    New XElement(ram + "ApplicableHeaderTradeSettlement",
                        New XElement(ram + "InvoiceCurrencyCode", "EUR"),
                        New XElement(ram + "SpecifiedTradeSettlementHeaderMonetarySummation",
                            New XElement(ram + "TaxBasisTotalAmount", invoice.Subtotal),
                            New XElement(ram + "TaxTotalAmount",
                                New XAttribute("currencyID", "EUR"),
                                invoice.Tax),
                            New XElement(ram + "GrandTotalAmount", invoice.Total),
                            New XElement(ram + "DuePayableAmount", invoice.Total)
                        )
                    )
                )
            )
        )

        ' Save the XML to a temp file for embedding
        Dim xmlPath As String = $"zugferd-{invoice.InvoiceNumber}.xml"
        zugferdXml.Save(xmlPath)

        ' Attach the XML to the PDF - filename must follow ZUGFeRD conventions
        pdf.Attachments.AddFile(xmlPath, "zugferd-invoice.xml", "ZUGFeRD Invoice Data")

        ' Final PDF contains both visual invoice and machine-readable XML
        pdf.SaveAs($"invoice-{invoice.InvoiceNumber}-zugferd.pdf")
    End Sub

    ' Generates simple HTML for the visual portion of the invoice
    Private Function BuildInvoiceHtml(invoice As Invoice) As String
        Return $"
<!DOCTYPE html>
<html>
<head>
    <style>
        body {{ font-family: Arial, sans-serif; padding: 40px; }}
        h1 {{ color: #333; }}
        .zugferd-notice {{ 
            margin-top: 30px; padding: 10px; 
            background: #f0f0f0; font-size: 11px; 
        }}
    </style>
</head>
<body>
    <h1>RECHNUNG / INVOICE</h1>
    <p><strong>Rechnungsnummer:</strong> {invoice.InvoiceNumber}</p>
    <p><strong>Datum:</strong> {invoice.InvoiceDate:dd.MM.yyyy}</p>
    <p><strong>Betrag:</strong> €{invoice.Total:F2}</p>

    <div class='zugferd-notice'>
        This invoice contains embedded ZUGFeRD data for automated processing.
    </div>
</body>
</html>"
    End Function
End Class
$vbLabelText   $csharpLabel

输出示例

合规性的主要方面是使用正确的 XML 命名空间、遵循 CII 架构结构以及以适当的文件名嵌入 XML。 类型代码 "380 "明确指出该文档是 UN/CEFACT 标准中的商业发票。

如何使发票符合欧盟要求

欧盟正在各成员国逐步推行电子发票。 意大利已经要求 B2B 交易必须使用电子发票，法国将在 2026 年前逐步实施相关要求，而德国已宣布从 2025 年开始强制实施 B2B 电子发票。现在就建立 ZUGFeRD/Factur-X 支持，为您的系统满足这些监管要求做好准备。

下面是一个合规感知发票生成器的模式，它可以针对不同的标准：

using IronPdf;
using System;

// Enum representing supported European e-invoicing standards
public enum InvoiceStandard
{
    None,
    ZUGFeRD,    // German standard - uses CII XML format
    FacturX,    // French standard - technically identical to ZUGFeRD 2.0
    Peppol      // Pan-European standard - uses UBL XML format
}

// Factory class that generates invoices compliant with different e-invoicing standards
// Allows switching between standards without changing core invoice generation logic
public class CompliantInvoiceGenerator
{
    public PdfDocument GenerateCompliantInvoice(Invoice invoice, InvoiceStandard standard)
    {
        // Generate the base PDF from HTML
        var renderer = new ChromePdfRenderer();
        string html = BuildInvoiceHtml(invoice);
        var pdf = renderer.RenderHtmlAsPdf(html);

        // Attach the appropriate XML format based on target market/regulation
        switch (standard)
        {
            case InvoiceStandard.ZUGFeRD:
            case InvoiceStandard.FacturX:
                // Both use Cross-Industry Invoice format, just different filenames
                EmbedCIIXmlData(pdf, invoice, standard);
                break;
            case InvoiceStandard.Peppol:
                // Peppol uses Universal Business Language format
                EmbedUBLXmlData(pdf, invoice);
                break;
        }

        return pdf;
    }

    // Creates and embeds CII-format XML (used by ZUGFeRD and Factur-X)
    private void EmbedCIIXmlData(PdfDocument pdf, Invoice invoice, InvoiceStandard standard)
    {
        string xml = GenerateCIIXml(invoice);

        // Filename convention differs between German and French standards
        string filename = standard == InvoiceStandard.ZUGFeRD
            ? "zugferd-invoice.xml"
            : "factur-x.xml";

        System.IO.File.WriteAllText("temp-invoice.xml", xml);
        pdf.Attachments.AddFile("temp-invoice.xml", filename, $"{standard} Invoice Data");
    }

    // Creates and embeds UBL-format XML for Peppol network compliance
    private void EmbedUBLXmlData(PdfDocument pdf, Invoice invoice)
    {
        // UBL (Universal Business Language) is the Peppol standard format
        string xml = $@"<?xml version='1.0' encoding='UTF-8'?>
<Invoice xmlns='urn:oasis:names:specification:ubl:schema:xsd:Invoice-2'>
    <ID>{invoice.InvoiceNumber}</ID>
    <IssueDate>{invoice.InvoiceDate:yyyy-MM-dd}</IssueDate>
    <DocumentCurrencyCode>EUR</DocumentCurrencyCode>
    <LegalMonetaryTotal>
        <PayableAmount currencyID='EUR'>{invoice.Total}</PayableAmount>
    </LegalMonetaryTotal>
</Invoice>";

        System.IO.File.WriteAllText("peppol-invoice.xml", xml);
        pdf.Attachments.AddFile("peppol-invoice.xml", "invoice.xml", "Peppol UBL Invoice");
    }

    // Generates minimal CII XML structure for demonstration
    private string GenerateCIIXml(Invoice invoice)
    {
        return $@"<?xml version='1.0' encoding='UTF-8'?>
<rsm:CrossIndustryInvoice
    xmlns:rsm='urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100'
    xmlns:ram='urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:100'>
    <rsm:ExchangedDocument>
        <ram:ID>{invoice.InvoiceNumber}</ram:ID>
        <ram:TypeCode>380</ram:TypeCode>
    </rsm:ExchangedDocument>
</rsm:CrossIndustryInvoice>";
    }

    private string BuildInvoiceHtml(Invoice invoice)
    {
        return $"<html><body><h1>Invoice {invoice.InvoiceNumber}</h1></body></html>";
    }
}
using IronPdf;
using System;

// Enum representing supported European e-invoicing standards
public enum InvoiceStandard
{
    None,
    ZUGFeRD,    // German standard - uses CII XML format
    FacturX,    // French standard - technically identical to ZUGFeRD 2.0
    Peppol      // Pan-European standard - uses UBL XML format
}

// Factory class that generates invoices compliant with different e-invoicing standards
// Allows switching between standards without changing core invoice generation logic
public class CompliantInvoiceGenerator
{
    public PdfDocument GenerateCompliantInvoice(Invoice invoice, InvoiceStandard standard)
    {
        // Generate the base PDF from HTML
        var renderer = new ChromePdfRenderer();
        string html = BuildInvoiceHtml(invoice);
        var pdf = renderer.RenderHtmlAsPdf(html);

        // Attach the appropriate XML format based on target market/regulation
        switch (standard)
        {
            case InvoiceStandard.ZUGFeRD:
            case InvoiceStandard.FacturX:
                // Both use Cross-Industry Invoice format, just different filenames
                EmbedCIIXmlData(pdf, invoice, standard);
                break;
            case InvoiceStandard.Peppol:
                // Peppol uses Universal Business Language format
                EmbedUBLXmlData(pdf, invoice);
                break;
        }

        return pdf;
    }

    // Creates and embeds CII-format XML (used by ZUGFeRD and Factur-X)
    private void EmbedCIIXmlData(PdfDocument pdf, Invoice invoice, InvoiceStandard standard)
    {
        string xml = GenerateCIIXml(invoice);

        // Filename convention differs between German and French standards
        string filename = standard == InvoiceStandard.ZUGFeRD
            ? "zugferd-invoice.xml"
            : "factur-x.xml";

        System.IO.File.WriteAllText("temp-invoice.xml", xml);
        pdf.Attachments.AddFile("temp-invoice.xml", filename, $"{standard} Invoice Data");
    }

    // Creates and embeds UBL-format XML for Peppol network compliance
    private void EmbedUBLXmlData(PdfDocument pdf, Invoice invoice)
    {
        // UBL (Universal Business Language) is the Peppol standard format
        string xml = $@"<?xml version='1.0' encoding='UTF-8'?>
<Invoice xmlns='urn:oasis:names:specification:ubl:schema:xsd:Invoice-2'>
    <ID>{invoice.InvoiceNumber}</ID>
    <IssueDate>{invoice.InvoiceDate:yyyy-MM-dd}</IssueDate>
    <DocumentCurrencyCode>EUR</DocumentCurrencyCode>
    <LegalMonetaryTotal>
        <PayableAmount currencyID='EUR'>{invoice.Total}</PayableAmount>
    </LegalMonetaryTotal>
</Invoice>";

        System.IO.File.WriteAllText("peppol-invoice.xml", xml);
        pdf.Attachments.AddFile("peppol-invoice.xml", "invoice.xml", "Peppol UBL Invoice");
    }

    // Generates minimal CII XML structure for demonstration
    private string GenerateCIIXml(Invoice invoice)
    {
        return $@"<?xml version='1.0' encoding='UTF-8'?>
<rsm:CrossIndustryInvoice
    xmlns:rsm='urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100'
    xmlns:ram='urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:100'>
    <rsm:ExchangedDocument>
        <ram:ID>{invoice.InvoiceNumber}</ram:ID>
        <ram:TypeCode>380</ram:TypeCode>
    </rsm:ExchangedDocument>
</rsm:CrossIndustryInvoice>";
    }

    private string BuildInvoiceHtml(Invoice invoice)
    {
        return $"<html><body><h1>Invoice {invoice.InvoiceNumber}</h1></body></html>";
    }
}
Imports IronPdf
Imports System

' Enum representing supported European e-invoicing standards
Public Enum InvoiceStandard
    None
    ZUGFeRD    ' German standard - uses CII XML format
    FacturX    ' French standard - technically identical to ZUGFeRD 2.0
    Peppol     ' Pan-European standard - uses UBL XML format
End Enum

' Factory class that generates invoices compliant with different e-invoicing standards
' Allows switching between standards without changing core invoice generation logic
Public Class CompliantInvoiceGenerator
    Public Function GenerateCompliantInvoice(invoice As Invoice, standard As InvoiceStandard) As PdfDocument
        ' Generate the base PDF from HTML
        Dim renderer As New ChromePdfRenderer()
        Dim html As String = BuildInvoiceHtml(invoice)
        Dim pdf As PdfDocument = renderer.RenderHtmlAsPdf(html)

        ' Attach the appropriate XML format based on target market/regulation
        Select Case standard
            Case InvoiceStandard.ZUGFeRD, InvoiceStandard.FacturX
                ' Both use Cross-Industry Invoice format, just different filenames
                EmbedCIIXmlData(pdf, invoice, standard)
            Case InvoiceStandard.Peppol
                ' Peppol uses Universal Business Language format
                EmbedUBLXmlData(pdf, invoice)
        End Select

        Return pdf
    End Function

    ' Creates and embeds CII-format XML (used by ZUGFeRD and Factur-X)
    Private Sub EmbedCIIXmlData(pdf As PdfDocument, invoice As Invoice, standard As InvoiceStandard)
        Dim xml As String = GenerateCIIXml(invoice)

        ' Filename convention differs between German and French standards
        Dim filename As String = If(standard = InvoiceStandard.ZUGFeRD, "zugferd-invoice.xml", "factur_x.xml")

        System.IO.File.WriteAllText("temp-invoice.xml", xml)
        pdf.Attachments.AddFile("temp-invoice.xml", filename, $"{standard} Invoice Data")
    End Sub

    ' Creates and embeds UBL-format XML for Peppol network compliance
    Private Sub EmbedUBLXmlData(pdf As PdfDocument, invoice As Invoice)
        ' UBL (Universal Business Language) is the Peppol standard format
        Dim xml As String = $"<?xml version='1.0' encoding='UTF-8'?>
<Invoice xmlns='urn:oasis:names:specification:ubl:schema:xsd:Invoice-2'>
    <ID>{invoice.InvoiceNumber}</ID>
    <IssueDate>{invoice.InvoiceDate:yyyy-MM-dd}</IssueDate>
    <DocumentCurrencyCode>EUR</DocumentCurrencyCode>
    <LegalMonetaryTotal>
        <PayableAmount currencyID='EUR'>{invoice.Total}</PayableAmount>
    </LegalMonetaryTotal>
</Invoice>"

        System.IO.File.WriteAllText("peppol-invoice.xml", xml)
        pdf.Attachments.AddFile("peppol-invoice.xml", "invoice.xml", "Peppol UBL Invoice")
    End Sub

    ' Generates minimal CII XML structure for demonstration
    Private Function GenerateCIIXml(invoice As Invoice) As String
        Return $"<?xml version='1.0' encoding='UTF-8'?>
<rsm:CrossIndustryInvoice
    xmlns:rsm='urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100'
    xmlns:ram='urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:100'>
    <rsm:ExchangedDocument>
        <ram:ID>{invoice.InvoiceNumber}</ram:ID>
        <ram:TypeCode>380</ram:TypeCode>
    </rsm:ExchangedDocument>
</rsm:CrossIndustryInvoice>"
    End Function

    Private Function BuildInvoiceHtml(invoice As Invoice) As String
        Return $"<html><body><h1>Invoice {invoice.InvoiceNumber}</h1></body></html>"
    End Function
End Class
$vbLabelText   $csharpLabel

这种架构允许您在新标准出现时添加新标准，而无需重组核心发票生成逻辑。 基于枚举的方法可以让用户或配置轻松决定使用哪种合规模式。

如何在 C# 中从 PDF 发票中提取数据;

生成发票只是成功的一半。 大多数企业也会收到来自供应商的发票，需要提取数据进行处理。 IronPDF 提供强大的文本提取功能，是发票数据采集的基础。

如何从 PDF 发票中提取文本

最基本的提取操作是从 PDF 中检索所有文本内容。 IronPDF 的 ExtractAllText 方法可处理 PDF 文本编码和定位的复杂性：

using IronPdf;
using System;

// Extracts raw text content from PDF invoices for further processing
public class InvoiceTextExtractor
{
    // Extracts all text from a PDF in one operation
    // Best for single-page invoices or when you need the complete content
    public string ExtractInvoiceText(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);

        // IronPDF handles the complexity of PDF text encoding and positioning
        string allText = pdf.ExtractAllText();
        Console.WriteLine("Full invoice text:");
        Console.WriteLine(allText);

        return allText;
    }

    // Extracts text page by page - useful for multi-page invoices
    // Allows you to process header info separately from line items
    public void ExtractTextByPage(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);

        // Iterate through each page (0-indexed)
        for (int i = 0; i < pdf.PageCount; i++)
        {
            string pageText = pdf.ExtractTextFromPage(i);
            Console.WriteLine($"\n--- Page {i + 1} ---");
            Console.WriteLine(pageText);
        }
    }
}
using IronPdf;
using System;

// Extracts raw text content from PDF invoices for further processing
public class InvoiceTextExtractor
{
    // Extracts all text from a PDF in one operation
    // Best for single-page invoices or when you need the complete content
    public string ExtractInvoiceText(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);

        // IronPDF handles the complexity of PDF text encoding and positioning
        string allText = pdf.ExtractAllText();
        Console.WriteLine("Full invoice text:");
        Console.WriteLine(allText);

        return allText;
    }

    // Extracts text page by page - useful for multi-page invoices
    // Allows you to process header info separately from line items
    public void ExtractTextByPage(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);

        // Iterate through each page (0-indexed)
        for (int i = 0; i < pdf.PageCount; i++)
        {
            string pageText = pdf.ExtractTextFromPage(i);
            Console.WriteLine($"\n--- Page {i + 1} ---");
            Console.WriteLine(pageText);
        }
    }
}
Imports IronPdf
Imports System

' Extracts raw text content from PDF invoices for further processing
Public Class InvoiceTextExtractor
    ' Extracts all text from a PDF in one operation
    ' Best for single-page invoices or when you need the complete content
    Public Function ExtractInvoiceText(pdfPath As String) As String
        Dim pdf = PdfDocument.FromFile(pdfPath)

        ' IronPDF handles the complexity of PDF text encoding and positioning
        Dim allText As String = pdf.ExtractAllText()
        Console.WriteLine("Full invoice text:")
        Console.WriteLine(allText)

        Return allText
    End Function

    ' Extracts text page by page - useful for multi-page invoices
    ' Allows you to process header info separately from line items
    Public Sub ExtractTextByPage(pdfPath As String)
        Dim pdf = PdfDocument.FromFile(pdfPath)

        ' Iterate through each page (0-indexed)
        For i As Integer = 0 To pdf.PageCount - 1
            Dim pageText As String = pdf.ExtractTextFromPage(i)
            Console.WriteLine(vbCrLf & "--- Page " & (i + 1).ToString() & " ---")
            Console.WriteLine(pageText)
        Next
    End Sub
End Class
$vbLabelText   $csharpLabel

逐页提取对于需要查找特定部分的多页发票特别有用，例如查找跨多页的细列项目，而标题信息只出现在第一页。

如何提取行项目的表数据

发票项目通常以表格形式出现。 PDF 缺乏原生表格结构，但您可以提取文本并进行解析，以重建表格数据：

using IronPdf;
using System;
using System.Collections.Generic;

// Data model for a single invoice line item
public class InvoiceLineItem
{
    public string Description { get; set; }
    public decimal Quantity { get; set; }
    public decimal UnitPrice { get; set; }
    public decimal Total { get; set; }
}

// Extracts tabular line item data from PDF invoices
// Note: PDFs don't have native table structure, so this uses text parsing
public class InvoiceTableExtractor
{
    public List<InvoiceLineItem> ExtractLineItems(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        var lineItems = new List<InvoiceLineItem>();
        string[] lines = text.Split('\n');

        foreach (string line in lines)
        {
            // Currency symbols indicate potential line items with amounts
            if (line.Contains("$") || line.Contains("€"))
            {
                Console.WriteLine($"Potential line item: {line.Trim()}");

                // Split on whitespace to separate columns
                // Actual parsing logic depends on your invoice format
                string[] parts = line.Split(new[] { '\t', ' ' },
                    StringSplitOptions.RemoveEmptyEntries);

                // Try to find numeric values that could be amounts
                foreach (string part in parts)
                {
                    string cleaned = part.Replace("$", "").Replace("€", "").Replace(",", "");
                    if (decimal.TryParse(cleaned, out decimal amount))
                    {
                        Console.WriteLine($"  Found amount: {amount:C}");
                    }
                }
            }
        }

        return lineItems;
    }
}
using IronPdf;
using System;
using System.Collections.Generic;

// Data model for a single invoice line item
public class InvoiceLineItem
{
    public string Description { get; set; }
    public decimal Quantity { get; set; }
    public decimal UnitPrice { get; set; }
    public decimal Total { get; set; }
}

// Extracts tabular line item data from PDF invoices
// Note: PDFs don't have native table structure, so this uses text parsing
public class InvoiceTableExtractor
{
    public List<InvoiceLineItem> ExtractLineItems(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        var lineItems = new List<InvoiceLineItem>();
        string[] lines = text.Split('\n');

        foreach (string line in lines)
        {
            // Currency symbols indicate potential line items with amounts
            if (line.Contains("$") || line.Contains("€"))
            {
                Console.WriteLine($"Potential line item: {line.Trim()}");

                // Split on whitespace to separate columns
                // Actual parsing logic depends on your invoice format
                string[] parts = line.Split(new[] { '\t', ' ' },
                    StringSplitOptions.RemoveEmptyEntries);

                // Try to find numeric values that could be amounts
                foreach (string part in parts)
                {
                    string cleaned = part.Replace("$", "").Replace("€", "").Replace(",", "");
                    if (decimal.TryParse(cleaned, out decimal amount))
                    {
                        Console.WriteLine($"  Found amount: {amount:C}");
                    }
                }
            }
        }

        return lineItems;
    }
}
Imports IronPdf
Imports System
Imports System.Collections.Generic

' Data model for a single invoice line item
Public Class InvoiceLineItem
    Public Property Description As String
    Public Property Quantity As Decimal
    Public Property UnitPrice As Decimal
    Public Property Total As Decimal
End Class

' Extracts tabular line item data from PDF invoices
' Note: PDFs don't have native table structure, so this uses text parsing
Public Class InvoiceTableExtractor
    Public Function ExtractLineItems(pdfPath As String) As List(Of InvoiceLineItem)
        Dim pdf = PdfDocument.FromFile(pdfPath)
        Dim text As String = pdf.ExtractAllText()

        Dim lineItems As New List(Of InvoiceLineItem)()
        Dim lines() As String = text.Split(ControlChars.Lf)

        For Each line As String In lines
            ' Currency symbols indicate potential line items with amounts
            If line.Contains("$") OrElse line.Contains("€") Then
                Console.WriteLine($"Potential line item: {line.Trim()}")

                ' Split on whitespace to separate columns
                ' Actual parsing logic depends on your invoice format
                Dim parts() As String = line.Split(New Char() {ControlChars.Tab, " "c}, StringSplitOptions.RemoveEmptyEntries)

                ' Try to find numeric values that could be amounts
                For Each part As String In parts
                    Dim cleaned As String = part.Replace("$", "").Replace("€", "").Replace(",", "")
                    Dim amount As Decimal
                    If Decimal.TryParse(cleaned, amount) Then
                        Console.WriteLine($"  Found amount: {amount:C}")
                    End If
                Next
            End If
        Next

        Return lineItems
    End Function
End Class
$vbLabelText   $csharpLabel

解析逻辑将根据您的发票格式而有所不同。 对于已知供应商具有一致布局的发票，您可以构建特定格式的解析器。 对于不同的格式，可以考虑本文后面介绍的人工智能提取。

如何对发票号码、日期和总数使用模式匹配

正则表达式对于从发票文本中提取特定数据点非常有用。 发票号码、日期和总额等关键字段通常遵循可识别的模式：

using IronPdf;
using System;
using System.Text.RegularExpressions;

// Data model for extracted invoice information
public class InvoiceData
{
    public string InvoiceNumber { get; set; }
    public string InvoiceDate { get; set; }
    public decimal TotalAmount { get; set; }
    public string VendorName { get; set; }
}

// Extracts key invoice fields using regex pattern matching
// Multiple patterns handle variations across different vendors
public class InvoiceParser
{
    public InvoiceData ParseInvoice(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        var invoiceData = new InvoiceData();

        // Try multiple patterns to find invoice number
        // Handles: "Invoice #123", "INV-123", "Invoice Number: 123", German "Rechnungsnummer"
        string[] invoiceNumberPatterns = new[]
        {
            @"Invoice\s*#?\s*:?\s*([A-Z0-9-]+)",
            @"INV[-\s]?(\d+)",
            @"Invoice\s+Number\s*:?\s*([A-Z0-9-]+)",
            @"Rechnungsnummer\s*:?\s*([A-Z0-9-]+)"
        };

        foreach (string pattern in invoiceNumberPatterns)
        {
            var match = Regex.Match(text, pattern, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                invoiceData.InvoiceNumber = match.Groups[1].Value;
                Console.WriteLine($"Found Invoice Number: {invoiceData.InvoiceNumber}");
                break;
            }
        }

        // Date patterns for US, European, and written formats
        string[] datePatterns = new[]
        {
            @"Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})",
            @"Invoice\s+Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})",
            @"(\d{1,2}\.\d{1,2}\.\d{4})",  // European: DD.MM.YYYY
            @"(\w+\s+\d{1,2},?\s+\d{4})"   // Written: January 15, 2024
        };

        foreach (string pattern in datePatterns)
        {
            var match = Regex.Match(text, pattern, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                invoiceData.InvoiceDate = match.Groups[1].Value;
                Console.WriteLine($"Found Date: {invoiceData.InvoiceDate}");
                break;
            }
        }

        // Look for total amount with various labels
        string[] totalPatterns = new[]
        {
            @"Total\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            @"Amount\s+Due\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            @"Grand\s+Total\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            @"Balance\s+Due\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})"
        };

        foreach (string pattern in totalPatterns)
        {
            var match = Regex.Match(text, pattern, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                // Remove commas before parsing
                string amountStr = match.Groups[1].Value.Replace(",", "");
                if (decimal.TryParse(amountStr, out decimal amount))
                {
                    invoiceData.TotalAmount = amount;
                    Console.WriteLine($"Found Total: ${invoiceData.TotalAmount:F2}");
                    break;
                }
            }
        }

        return invoiceData;
    }
}
using IronPdf;
using System;
using System.Text.RegularExpressions;

// Data model for extracted invoice information
public class InvoiceData
{
    public string InvoiceNumber { get; set; }
    public string InvoiceDate { get; set; }
    public decimal TotalAmount { get; set; }
    public string VendorName { get; set; }
}

// Extracts key invoice fields using regex pattern matching
// Multiple patterns handle variations across different vendors
public class InvoiceParser
{
    public InvoiceData ParseInvoice(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        var invoiceData = new InvoiceData();

        // Try multiple patterns to find invoice number
        // Handles: "Invoice #123", "INV-123", "Invoice Number: 123", German "Rechnungsnummer"
        string[] invoiceNumberPatterns = new[]
        {
            @"Invoice\s*#?\s*:?\s*([A-Z0-9-]+)",
            @"INV[-\s]?(\d+)",
            @"Invoice\s+Number\s*:?\s*([A-Z0-9-]+)",
            @"Rechnungsnummer\s*:?\s*([A-Z0-9-]+)"
        };

        foreach (string pattern in invoiceNumberPatterns)
        {
            var match = Regex.Match(text, pattern, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                invoiceData.InvoiceNumber = match.Groups[1].Value;
                Console.WriteLine($"Found Invoice Number: {invoiceData.InvoiceNumber}");
                break;
            }
        }

        // Date patterns for US, European, and written formats
        string[] datePatterns = new[]
        {
            @"Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})",
            @"Invoice\s+Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})",
            @"(\d{1,2}\.\d{1,2}\.\d{4})",  // European: DD.MM.YYYY
            @"(\w+\s+\d{1,2},?\s+\d{4})"   // Written: January 15, 2024
        };

        foreach (string pattern in datePatterns)
        {
            var match = Regex.Match(text, pattern, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                invoiceData.InvoiceDate = match.Groups[1].Value;
                Console.WriteLine($"Found Date: {invoiceData.InvoiceDate}");
                break;
            }
        }

        // Look for total amount with various labels
        string[] totalPatterns = new[]
        {
            @"Total\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            @"Amount\s+Due\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            @"Grand\s+Total\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            @"Balance\s+Due\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})"
        };

        foreach (string pattern in totalPatterns)
        {
            var match = Regex.Match(text, pattern, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                // Remove commas before parsing
                string amountStr = match.Groups[1].Value.Replace(",", "");
                if (decimal.TryParse(amountStr, out decimal amount))
                {
                    invoiceData.TotalAmount = amount;
                    Console.WriteLine($"Found Total: ${invoiceData.TotalAmount:F2}");
                    break;
                }
            }
        }

        return invoiceData;
    }
}
Imports IronPdf
Imports System
Imports System.Text.RegularExpressions

' Data model for extracted invoice information
Public Class InvoiceData
    Public Property InvoiceNumber As String
    Public Property InvoiceDate As String
    Public Property TotalAmount As Decimal
    Public Property VendorName As String
End Class

' Extracts key invoice fields using regex pattern matching
' Multiple patterns handle variations across different vendors
Public Class InvoiceParser
    Public Function ParseInvoice(pdfPath As String) As InvoiceData
        Dim pdf = PdfDocument.FromFile(pdfPath)
        Dim text As String = pdf.ExtractAllText()

        Dim invoiceData As New InvoiceData()

        ' Try multiple patterns to find invoice number
        ' Handles: "Invoice #123", "INV-123", "Invoice Number: 123", German "Rechnungsnummer"
        Dim invoiceNumberPatterns As String() = {
            "Invoice\s*#?\s*:?\s*([A-Z0-9-]+)",
            "INV[-\s]?(\d+)",
            "Invoice\s+Number\s*:?\s*([A-Z0-9-]+)",
            "Rechnungsnummer\s*:?\s*([A-Z0-9-]+)"
        }

        For Each pattern As String In invoiceNumberPatterns
            Dim match = Regex.Match(text, pattern, RegexOptions.IgnoreCase)
            If match.Success Then
                invoiceData.InvoiceNumber = match.Groups(1).Value
                Console.WriteLine($"Found Invoice Number: {invoiceData.InvoiceNumber}")
                Exit For
            End If
        Next

        ' Date patterns for US, European, and written formats
        Dim datePatterns As String() = {
            "Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})",
            "Invoice\s+Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})",
            "(\d{1,2}\.\d{1,2}\.\d{4})",  ' European: DD.MM.YYYY
            "(\w+\s+\d{1,2},?\s+\d{4})"   ' Written: January 15, 2024
        }

        For Each pattern As String In datePatterns
            Dim match = Regex.Match(text, pattern, RegexOptions.IgnoreCase)
            If match.Success Then
                invoiceData.InvoiceDate = match.Groups(1).Value
                Console.WriteLine($"Found Date: {invoiceData.InvoiceDate}")
                Exit For
            End If
        Next

        ' Look for total amount with various labels
        Dim totalPatterns As String() = {
            "Total\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            "Amount\s+Due\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            "Grand\s+Total\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})",
            "Balance\s+Due\s*:?\s*[\$€]?\s*([\d,]+\.\d{2})"
        }

        For Each pattern As String In totalPatterns
            Dim match = Regex.Match(text, pattern, RegexOptions.IgnoreCase)
            If match.Success Then
                ' Remove commas before parsing
                Dim amountStr As String = match.Groups(1).Value.Replace(",", "")
                Dim amount As Decimal
                If Decimal.TryParse(amountStr, amount) Then
                    invoiceData.TotalAmount = amount
                    Console.WriteLine($"Found Total: ${invoiceData.TotalAmount:F2}")
                    Exit For
                End If
            End If
        Next

        Return invoiceData
    End Function
End Class
$vbLabelText   $csharpLabel

这种基于模式的方法对于具有可预测格式的发票非常有效。 多种模式变化可处理不同供应商之间常见的格式差异，如 "发票＃"和 "发票号码："。

扫描发票或基于图像的发票怎么办？

上述文本提取方法适用于包含嵌入文本的 PDF。 然而，扫描文件和基于图像的 PDF 没有可提取的文本。 它们基本上是发票的图片。

请注意处理扫描发票时，您需要 OCR（光学字符识别）功能。 IronOCR 是 Iron Suite 的一部分，可与 IronPDF 无缝集成，用于这些场景。 请访问 https://ironsoftware.com/csharp/ocr/ 了解更多有关从扫描文档和图像中提取文本的信息。

如何在 .NET 中使用 AI 处理发票

传统的模式匹配对于标准化发票非常有效，但现实世界中应付账款部门收到的文件格式数不胜数。 这正是人工智能提取技术的优势所在。 大型语言模型可以理解发票语义，甚至可以从陌生的布局中提取结构化数据。

如何将人工智能整合到发票解析中

人工智能驱动的发票处理模式结合了 IronPDF 的文本提取和 LLM API 调用。 下面是一个通用的实现方法，可与任何兼容 OpenAI 的 API 配合使用：

using IronPdf;
using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

// Data model for extracted invoice information
public class InvoiceData
{
    public string InvoiceNumber { get; set; }
    public string InvoiceDate { get; set; }
    public string VendorName { get; set; }
    public decimal TotalAmount { get; set; }
}

// Leverages AI/LLM APIs to extract structured data from any invoice format
// Works with OpenAI or any compatible API endpoint
public class AIInvoiceParser
{
    private readonly HttpClient _httpClient;
    private readonly string _apiKey;
    private readonly string _apiUrl;

    public AIInvoiceParser(string apiKey, string apiUrl = "https://api.openai.com/v1/chat/completions")
    {
        _apiKey = apiKey;
        _apiUrl = apiUrl;
        _httpClient = new HttpClient();
        _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_apiKey}");
    }

    public async Task<InvoiceData> ParseInvoiceWithAI(string pdfPath)
    {
        // First extract raw text from the PDF using IronPDF
        var pdf = PdfDocument.FromFile(pdfPath);
        string invoiceText = pdf.ExtractAllText();

        // Construct a prompt that instructs the AI to return structured JSON
        // Being explicit about the format reduces parsing errors
        string prompt = $@"Extract the following information from this invoice text.
Return ONLY valid JSON with no additional text or markdown formatting.

Required fields:
- InvoiceNumber: The invoice or document number
- InvoiceDate: The invoice date in YYYY-MM-DD format
- VendorName: The company or person who sent the invoice
- TotalAmount: The total amount due as a number (no currency symbols)

Invoice text:
{invoiceText}

JSON response:";

        // Build the API request with a system prompt for context
        var requestBody = new
        {
            model = "gpt-4",
            messages = new[]
            {
                new {
                    role = "system",
                    content = "You are an invoice data extraction assistant. Extract structured data from invoices and return valid JSON only."
                },
                new { role = "user", content = prompt }
            },
            temperature = 0.1  // Low temperature ensures consistent, deterministic results
        };

        var json = JsonSerializer.Serialize(requestBody);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        var response = await _httpClient.PostAsync(_apiUrl, content);
        var responseJson = await response.Content.ReadAsStringAsync();

        // Navigate the API response structure to get the extracted content
        using var doc = JsonDocument.Parse(responseJson);
        var messageContent = doc.RootElement
            .GetProperty("choices")[0]
            .GetProperty("message")
            .GetProperty("content")
            .GetString();

        Console.WriteLine("AI Extracted Data:");
        Console.WriteLine(messageContent);

        // Deserialize the AI's JSON response into our data class
        var invoiceData = JsonSerializer.Deserialize<InvoiceData>(messageContent,
            new JsonSerializerOptions { PropertyNameCaseInsensitive = true });

        return invoiceData;
    }
}
using IronPdf;
using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

// Data model for extracted invoice information
public class InvoiceData
{
    public string InvoiceNumber { get; set; }
    public string InvoiceDate { get; set; }
    public string VendorName { get; set; }
    public decimal TotalAmount { get; set; }
}

// Leverages AI/LLM APIs to extract structured data from any invoice format
// Works with OpenAI or any compatible API endpoint
public class AIInvoiceParser
{
    private readonly HttpClient _httpClient;
    private readonly string _apiKey;
    private readonly string _apiUrl;

    public AIInvoiceParser(string apiKey, string apiUrl = "https://api.openai.com/v1/chat/completions")
    {
        _apiKey = apiKey;
        _apiUrl = apiUrl;
        _httpClient = new HttpClient();
        _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_apiKey}");
    }

    public async Task<InvoiceData> ParseInvoiceWithAI(string pdfPath)
    {
        // First extract raw text from the PDF using IronPDF
        var pdf = PdfDocument.FromFile(pdfPath);
        string invoiceText = pdf.ExtractAllText();

        // Construct a prompt that instructs the AI to return structured JSON
        // Being explicit about the format reduces parsing errors
        string prompt = $@"Extract the following information from this invoice text.
Return ONLY valid JSON with no additional text or markdown formatting.

Required fields:
- InvoiceNumber: The invoice or document number
- InvoiceDate: The invoice date in YYYY-MM-DD format
- VendorName: The company or person who sent the invoice
- TotalAmount: The total amount due as a number (no currency symbols)

Invoice text:
{invoiceText}

JSON response:";

        // Build the API request with a system prompt for context
        var requestBody = new
        {
            model = "gpt-4",
            messages = new[]
            {
                new {
                    role = "system",
                    content = "You are an invoice data extraction assistant. Extract structured data from invoices and return valid JSON only."
                },
                new { role = "user", content = prompt }
            },
            temperature = 0.1  // Low temperature ensures consistent, deterministic results
        };

        var json = JsonSerializer.Serialize(requestBody);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        var response = await _httpClient.PostAsync(_apiUrl, content);
        var responseJson = await response.Content.ReadAsStringAsync();

        // Navigate the API response structure to get the extracted content
        using var doc = JsonDocument.Parse(responseJson);
        var messageContent = doc.RootElement
            .GetProperty("choices")[0]
            .GetProperty("message")
            .GetProperty("content")
            .GetString();

        Console.WriteLine("AI Extracted Data:");
        Console.WriteLine(messageContent);

        // Deserialize the AI's JSON response into our data class
        var invoiceData = JsonSerializer.Deserialize<InvoiceData>(messageContent,
            new JsonSerializerOptions { PropertyNameCaseInsensitive = true });

        return invoiceData;
    }
}
Imports IronPdf
Imports System
Imports System.Net.Http
Imports System.Text
Imports System.Text.Json
Imports System.Threading.Tasks

' Data model for extracted invoice information
Public Class InvoiceData
    Public Property InvoiceNumber As String
    Public Property InvoiceDate As String
    Public Property VendorName As String
    Public Property TotalAmount As Decimal
End Class

' Leverages AI/LLM APIs to extract structured data from any invoice format
' Works with OpenAI or any compatible API endpoint
Public Class AIInvoiceParser
    Private ReadOnly _httpClient As HttpClient
    Private ReadOnly _apiKey As String
    Private ReadOnly _apiUrl As String

    Public Sub New(apiKey As String, Optional apiUrl As String = "https://api.openai.com/v1/chat/completions")
        _apiKey = apiKey
        _apiUrl = apiUrl
        _httpClient = New HttpClient()
        _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_apiKey}")
    End Sub

    Public Async Function ParseInvoiceWithAI(pdfPath As String) As Task(Of InvoiceData)
        ' First extract raw text from the PDF using IronPDF
        Dim pdf = PdfDocument.FromFile(pdfPath)
        Dim invoiceText As String = pdf.ExtractAllText()

        ' Construct a prompt that instructs the AI to return structured JSON
        ' Being explicit about the format reduces parsing errors
        Dim prompt As String = $"Extract the following information from this invoice text.
Return ONLY valid JSON with no additional text or markdown formatting.

Required fields:
- InvoiceNumber: The invoice or document number
- InvoiceDate: The invoice date in YYYY-MM-DD format
- VendorName: The company or person who sent the invoice
- TotalAmount: The total amount due as a number (no currency symbols)

Invoice text:
{invoiceText}

JSON response:"

        ' Build the API request with a system prompt for context
        Dim requestBody = New With {
            .model = "gpt-4",
            .messages = New Object() {
                New With {
                    .role = "system",
                    .content = "You are an invoice data extraction assistant. Extract structured data from invoices and return valid JSON only."
                },
                New With {
                    .role = "user",
                    .content = prompt
                }
            },
            .temperature = 0.1  ' Low temperature ensures consistent, deterministic results
        }

        Dim json As String = JsonSerializer.Serialize(requestBody)
        Dim content As New StringContent(json, Encoding.UTF8, "application/json")

        Dim response = Await _httpClient.PostAsync(_apiUrl, content)
        Dim responseJson As String = Await response.Content.ReadAsStringAsync()

        ' Navigate the API response structure to get the extracted content
        Using doc = JsonDocument.Parse(responseJson)
            Dim messageContent As String = doc.RootElement _
                .GetProperty("choices")(0) _
                .GetProperty("message") _
                .GetProperty("content") _
                .GetString()

            Console.WriteLine("AI Extracted Data:")
            Console.WriteLine(messageContent)

            ' Deserialize the AI's JSON response into our data class
            Dim invoiceData As InvoiceData = JsonSerializer.Deserialize(Of InvoiceData)(messageContent, New JsonSerializerOptions With {.PropertyNameCaseInsensitive = True})

            Return invoiceData
        End Using
    End Function
End Class
$vbLabelText   $csharpLabel

低温设置（0.1）鼓励确定性输出，这对于数据提取任务非常重要，因为您希望相同输入结果一致。

如何从发票中提取结构化 JSON 数据

对于包含细列项目、供应商详细信息和客户信息的更复杂发票，您可以要求使用更丰富的 JSON 结构：

using IronPdf;
using System;
using System.Collections.Generic;
using System.Text.Json;
using System.Threading.Tasks;

// Comprehensive invoice data model with all details
public class DetailedInvoiceData
{
    public string InvoiceNumber { get; set; }
    public DateTime InvoiceDate { get; set; }
    public DateTime DueDate { get; set; }
    public VendorInfo Vendor { get; set; }
    public CustomerInfo Customer { get; set; }
    public List<LineItem> LineItems { get; set; }
    public decimal Subtotal { get; set; }
    public decimal Tax { get; set; }
    public decimal Total { get; set; }
}

public class VendorInfo
{
    public string Name { get; set; }
    public string Address { get; set; }
    public string TaxId { get; set; }
}

public class CustomerInfo
{
    public string Name { get; set; }
    public string Address { get; set; }
}

public class LineItem
{
    public string Description { get; set; }
    public decimal Quantity { get; set; }
    public decimal UnitPrice { get; set; }
    public decimal Total { get; set; }
}

// Extracts comprehensive invoice data including line items and party details
public class StructuredInvoiceExtractor
{
    private readonly AIInvoiceParser _aiParser;

    public StructuredInvoiceExtractor(string apiKey)
    {
        _aiParser = new AIInvoiceParser(apiKey);
    }

    public async Task<DetailedInvoiceData> ExtractDetailedData(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        // Define the exact JSON structure we want the AI to return
        // This schema guides the AI to extract all relevant fields
        string jsonSchema = @"{
  ""InvoiceNumber"": ""string"",
  ""InvoiceDate"": ""YYYY-MM-DD"",
  ""DueDate"": ""YYYY-MM-DD"",
  ""Vendor"": {
    ""Name"": ""string"",
    ""Address"": ""string"",
    ""TaxId"": ""string or null""
  },
  ""Customer"": {
    ""Name"": ""string"",
    ""Address"": ""string""
  },
  ""LineItems"": [
    {
      ""Description"": ""string"",
      ""Quantity"": 0.0,
      ""UnitPrice"": 0.00,
      ""Total"": 0.00
    }
  ],
  ""Subtotal"": 0.00,
  ""Tax"": 0.00,
  ""Total"": 0.00
}";

        // Prompt includes both the schema and the extracted text
        string prompt = $@"Extract all invoice data and return it in this exact JSON structure:
{jsonSchema}

Invoice text:
{text}

Return only valid JSON, no markdown formatting or additional text.";

        // Call AI API and parse response (implementation as shown above)
        // Return deserialized DetailedInvoiceData

        return new DetailedInvoiceData(); // Placeholder
    }
}
using IronPdf;
using System;
using System.Collections.Generic;
using System.Text.Json;
using System.Threading.Tasks;

// Comprehensive invoice data model with all details
public class DetailedInvoiceData
{
    public string InvoiceNumber { get; set; }
    public DateTime InvoiceDate { get; set; }
    public DateTime DueDate { get; set; }
    public VendorInfo Vendor { get; set; }
    public CustomerInfo Customer { get; set; }
    public List<LineItem> LineItems { get; set; }
    public decimal Subtotal { get; set; }
    public decimal Tax { get; set; }
    public decimal Total { get; set; }
}

public class VendorInfo
{
    public string Name { get; set; }
    public string Address { get; set; }
    public string TaxId { get; set; }
}

public class CustomerInfo
{
    public string Name { get; set; }
    public string Address { get; set; }
}

public class LineItem
{
    public string Description { get; set; }
    public decimal Quantity { get; set; }
    public decimal UnitPrice { get; set; }
    public decimal Total { get; set; }
}

// Extracts comprehensive invoice data including line items and party details
public class StructuredInvoiceExtractor
{
    private readonly AIInvoiceParser _aiParser;

    public StructuredInvoiceExtractor(string apiKey)
    {
        _aiParser = new AIInvoiceParser(apiKey);
    }

    public async Task<DetailedInvoiceData> ExtractDetailedData(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        // Define the exact JSON structure we want the AI to return
        // This schema guides the AI to extract all relevant fields
        string jsonSchema = @"{
  ""InvoiceNumber"": ""string"",
  ""InvoiceDate"": ""YYYY-MM-DD"",
  ""DueDate"": ""YYYY-MM-DD"",
  ""Vendor"": {
    ""Name"": ""string"",
    ""Address"": ""string"",
    ""TaxId"": ""string or null""
  },
  ""Customer"": {
    ""Name"": ""string"",
    ""Address"": ""string""
  },
  ""LineItems"": [
    {
      ""Description"": ""string"",
      ""Quantity"": 0.0,
      ""UnitPrice"": 0.00,
      ""Total"": 0.00
    }
  ],
  ""Subtotal"": 0.00,
  ""Tax"": 0.00,
  ""Total"": 0.00
}";

        // Prompt includes both the schema and the extracted text
        string prompt = $@"Extract all invoice data and return it in this exact JSON structure:
{jsonSchema}

Invoice text:
{text}

Return only valid JSON, no markdown formatting or additional text.";

        // Call AI API and parse response (implementation as shown above)
        // Return deserialized DetailedInvoiceData

        return new DetailedInvoiceData(); // Placeholder
    }
}
Imports IronPdf
Imports System
Imports System.Collections.Generic
Imports System.Text.Json
Imports System.Threading.Tasks

' Comprehensive invoice data model with all details
Public Class DetailedInvoiceData
    Public Property InvoiceNumber As String
    Public Property InvoiceDate As DateTime
    Public Property DueDate As DateTime
    Public Property Vendor As VendorInfo
    Public Property Customer As CustomerInfo
    Public Property LineItems As List(Of LineItem)
    Public Property Subtotal As Decimal
    Public Property Tax As Decimal
    Public Property Total As Decimal
End Class

Public Class VendorInfo
    Public Property Name As String
    Public Property Address As String
    Public Property TaxId As String
End Class

Public Class CustomerInfo
    Public Property Name As String
    Public Property Address As String
End Class

Public Class LineItem
    Public Property Description As String
    Public Property Quantity As Decimal
    Public Property UnitPrice As Decimal
    Public Property Total As Decimal
End Class

' Extracts comprehensive invoice data including line items and party details
Public Class StructuredInvoiceExtractor
    Private ReadOnly _aiParser As AIInvoiceParser

    Public Sub New(apiKey As String)
        _aiParser = New AIInvoiceParser(apiKey)
    End Sub

    Public Async Function ExtractDetailedData(pdfPath As String) As Task(Of DetailedInvoiceData)
        Dim pdf = PdfDocument.FromFile(pdfPath)
        Dim text As String = pdf.ExtractAllText()

        ' Define the exact JSON structure we want the AI to return
        ' This schema guides the AI to extract all relevant fields
        Dim jsonSchema As String = "{
  ""InvoiceNumber"": ""string"",
  ""InvoiceDate"": ""YYYY-MM-DD"",
  ""DueDate"": ""YYYY-MM-DD"",
  ""Vendor"": {
    ""Name"": ""string"",
    ""Address"": ""string"",
    ""TaxId"": ""string or null""
  },
  ""Customer"": {
    ""Name"": ""string"",
    ""Address"": ""string""
  },
  ""LineItems"": [
    {
      ""Description"": ""string"",
      ""Quantity"": 0.0,
      ""UnitPrice"": 0.00,
      ""Total"": 0.00
    }
  ],
  ""Subtotal"": 0.00,
  ""Tax"": 0.00,
  ""Total"": 0.00
}"

        ' Prompt includes both the schema and the extracted text
        Dim prompt As String = $"
Extract all invoice data and return it in this exact JSON structure:
{jsonSchema}

Invoice text:
{text}

Return only valid JSON, no markdown formatting or additional text."

        ' Call AI API and parse response (implementation as shown above)
        ' Return deserialized DetailedInvoiceData

        Return New DetailedInvoiceData() ' Placeholder
    End Function
End Class
$vbLabelText   $csharpLabel

如何处理不一致的发票格式

在处理来自多个供应商的发票时，人工智能提取的真正威力就显现出来了，每个供应商都有自己独特的格式。 智能处理器可以首先尝试基于模式的提取（更快、更自由），只有在需要时才使用人工智能：

using IronPdf;
using System.Threading.Tasks;

// Hybrid processor that optimizes for cost and capability
// Tries fast regex patterns first, uses AI only when patterns fail
public class SmartInvoiceProcessor
{
    private readonly AIInvoiceParser _aiParser;

    public SmartInvoiceProcessor(string aiApiKey)
    {
        _aiParser = new AIInvoiceParser(aiApiKey);
    }

    public async Task<InvoiceData> ProcessAnyInvoice(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        // First attempt: regex patterns (fast and free)
        var patternParser = new InvoiceParser();
        var standardResult = patternParser.ParseInvoiceFromText(text);

        // If pattern matching found all required fields, use that result
        if (IsComplete(standardResult))
        {
            Console.WriteLine("Pattern extraction successful");
            return standardResult;
        }

        // Fallback: use AI for complex or unusual invoice formats
        // This costs money but handles any layout
        Console.WriteLine("Using AI extraction for complex invoice format");
        var aiResult = await _aiParser.ParseInvoiceWithAI(pdfPath);

        return aiResult;
    }

    // Validates that we have the minimum required fields
    private bool IsComplete(InvoiceData data)
    {
        return !string.IsNullOrEmpty(data.InvoiceNumber) &&
               !string.IsNullOrEmpty(data.InvoiceDate) &&
               data.TotalAmount > 0;
    }
}
using IronPdf;
using System.Threading.Tasks;

// Hybrid processor that optimizes for cost and capability
// Tries fast regex patterns first, uses AI only when patterns fail
public class SmartInvoiceProcessor
{
    private readonly AIInvoiceParser _aiParser;

    public SmartInvoiceProcessor(string aiApiKey)
    {
        _aiParser = new AIInvoiceParser(aiApiKey);
    }

    public async Task<InvoiceData> ProcessAnyInvoice(string pdfPath)
    {
        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        // First attempt: regex patterns (fast and free)
        var patternParser = new InvoiceParser();
        var standardResult = patternParser.ParseInvoiceFromText(text);

        // If pattern matching found all required fields, use that result
        if (IsComplete(standardResult))
        {
            Console.WriteLine("Pattern extraction successful");
            return standardResult;
        }

        // Fallback: use AI for complex or unusual invoice formats
        // This costs money but handles any layout
        Console.WriteLine("Using AI extraction for complex invoice format");
        var aiResult = await _aiParser.ParseInvoiceWithAI(pdfPath);

        return aiResult;
    }

    // Validates that we have the minimum required fields
    private bool IsComplete(InvoiceData data)
    {
        return !string.IsNullOrEmpty(data.InvoiceNumber) &&
               !string.IsNullOrEmpty(data.InvoiceDate) &&
               data.TotalAmount > 0;
    }
}
Imports IronPdf
Imports System.Threading.Tasks

' Hybrid processor that optimizes for cost and capability
' Tries fast regex patterns first, uses AI only when patterns fail
Public Class SmartInvoiceProcessor
    Private ReadOnly _aiParser As AIInvoiceParser

    Public Sub New(aiApiKey As String)
        _aiParser = New AIInvoiceParser(aiApiKey)
    End Sub

    Public Async Function ProcessAnyInvoice(pdfPath As String) As Task(Of InvoiceData)
        Dim pdf = PdfDocument.FromFile(pdfPath)
        Dim text As String = pdf.ExtractAllText()

        ' First attempt: regex patterns (fast and free)
        Dim patternParser = New InvoiceParser()
        Dim standardResult = patternParser.ParseInvoiceFromText(text)

        ' If pattern matching found all required fields, use that result
        If IsComplete(standardResult) Then
            Console.WriteLine("Pattern extraction successful")
            Return standardResult
        End If

        ' Fallback: use AI for complex or unusual invoice formats
        ' This costs money but handles any layout
        Console.WriteLine("Using AI extraction for complex invoice format")
        Dim aiResult = Await _aiParser.ParseInvoiceWithAI(pdfPath)

        Return aiResult
    End Function

    ' Validates that we have the minimum required fields
    Private Function IsComplete(data As InvoiceData) As Boolean
        Return Not String.IsNullOrEmpty(data.InvoiceNumber) AndAlso
               Not String.IsNullOrEmpty(data.InvoiceDate) AndAlso
               data.TotalAmount > 0
    End Function
End Class
$vbLabelText   $csharpLabel

如何构建应付账款自动化管道

将所有这些部分整合在一起，这就是一个完整的自动化管道，它可以处理收到的发票、提取数据、验证数据并为您的会计系统做好准备：

using IronPdf;
using System;
using System.IO;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Linq;

// Tracks the outcome of processing each invoice
public class ProcessingResult
{
    public string FileName { get; set; }
    public bool Success { get; set; }
    public string InvoiceNumber { get; set; }
    public string ErrorMessage { get; set; }
}

// Complete automation pipeline for accounts payable
// Watches a folder, extracts data, validates, and routes to accounting system
public class InvoiceAutomationPipeline
{
    private readonly SmartInvoiceProcessor _processor;
    private readonly string _inputFolder;
    private readonly string _processedFolder;
    private readonly string _errorFolder;

    public InvoiceAutomationPipeline(string apiKey, string inputFolder)
    {
        _processor = new SmartInvoiceProcessor(apiKey);
        _inputFolder = inputFolder;
        _processedFolder = Path.Combine(inputFolder, "processed");
        _errorFolder = Path.Combine(inputFolder, "errors");

        // Create output directories if they don't exist
        Directory.CreateDirectory(_processedFolder);
        Directory.CreateDirectory(_errorFolder);
    }

    // Main entry point - processes all PDFs in the input folder
    public async Task<List<ProcessingResult>> ProcessInvoiceBatch()
    {
        string[] invoiceFiles = Directory.GetFiles(_inputFolder, "*.pdf");
        Console.WriteLine($"Found {invoiceFiles.Length} invoices to process");

        var results = new List<ProcessingResult>();

        foreach (string invoicePath in invoiceFiles)
        {
            string fileName = Path.GetFileName(invoicePath);

            try
            {
                Console.WriteLine($"Processing: {fileName}");

                // Extract data using smart processor (patterns first, then AI)
                var invoiceData = await _processor.ProcessAnyInvoice(invoicePath);

                // Ensure we have minimum required fields before proceeding
                if (ValidateInvoiceData(invoiceData))
                {
                    // Send to accounting system (QuickBooks, Xero, etc.)
                    await SaveToAccountingSystem(invoiceData);

                    // Archive successful invoices
                    string destPath = Path.Combine(_processedFolder, fileName);
                    File.Move(invoicePath, destPath, overwrite: true);

                    results.Add(new ProcessingResult
                    {
                        FileName = fileName,
                        Success = true,
                        InvoiceNumber = invoiceData.InvoiceNumber
                    });

                    Console.WriteLine($"✓ Processed: {invoiceData.InvoiceNumber}");
                }
                else
                {
                    throw new Exception("Validation failed - missing required fields");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"✗ Failed: {fileName} - {ex.Message}");

                // Quarantine failed invoices for manual review
                string destPath = Path.Combine(_errorFolder, fileName);
                File.Move(invoicePath, destPath, overwrite: true);

                results.Add(new ProcessingResult
                {
                    FileName = fileName,
                    Success = false,
                    ErrorMessage = ex.Message
                });
            }
        }

        GenerateReport(results);
        return results;
    }

    // Checks for minimum required fields
    private bool ValidateInvoiceData(InvoiceData data)
    {
        return !string.IsNullOrEmpty(data.InvoiceNumber) &&
               !string.IsNullOrEmpty(data.VendorName) &&
               data.TotalAmount > 0;
    }

    // Placeholder for accounting system integration
    private async Task SaveToAccountingSystem(InvoiceData data)
    {
        // Integrate with your accounting system here
        // Examples: QuickBooks API, Xero API, SAP, or database storage
        Console.WriteLine($"  Saved invoice {data.InvoiceNumber} to accounting system");
        await Task.CompletedTask;
    }

    // Outputs a summary of the batch processing results
    private void GenerateReport(List<ProcessingResult> results)
    {
        int successful = results.Count(r => r.Success);
        int failed = results.Count(r => !r.Success);

        Console.WriteLine($"\n========== Processing Complete ==========");
        Console.WriteLine($"Total Processed: {results.Count}");
        Console.WriteLine($"Successful: {successful}");
        Console.WriteLine($"Failed: {failed}");

        if (failed > 0)
        {
            Console.WriteLine("\nFailed invoices requiring review:");
            foreach (var failure in results.Where(r => !r.Success))
            {
                Console.WriteLine($"  • {failure.FileName}: {failure.ErrorMessage}");
            }
        }
    }
}
using IronPdf;
using System;
using System.IO;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Linq;

// Tracks the outcome of processing each invoice
public class ProcessingResult
{
    public string FileName { get; set; }
    public bool Success { get; set; }
    public string InvoiceNumber { get; set; }
    public string ErrorMessage { get; set; }
}

// Complete automation pipeline for accounts payable
// Watches a folder, extracts data, validates, and routes to accounting system
public class InvoiceAutomationPipeline
{
    private readonly SmartInvoiceProcessor _processor;
    private readonly string _inputFolder;
    private readonly string _processedFolder;
    private readonly string _errorFolder;

    public InvoiceAutomationPipeline(string apiKey, string inputFolder)
    {
        _processor = new SmartInvoiceProcessor(apiKey);
        _inputFolder = inputFolder;
        _processedFolder = Path.Combine(inputFolder, "processed");
        _errorFolder = Path.Combine(inputFolder, "errors");

        // Create output directories if they don't exist
        Directory.CreateDirectory(_processedFolder);
        Directory.CreateDirectory(_errorFolder);
    }

    // Main entry point - processes all PDFs in the input folder
    public async Task<List<ProcessingResult>> ProcessInvoiceBatch()
    {
        string[] invoiceFiles = Directory.GetFiles(_inputFolder, "*.pdf");
        Console.WriteLine($"Found {invoiceFiles.Length} invoices to process");

        var results = new List<ProcessingResult>();

        foreach (string invoicePath in invoiceFiles)
        {
            string fileName = Path.GetFileName(invoicePath);

            try
            {
                Console.WriteLine($"Processing: {fileName}");

                // Extract data using smart processor (patterns first, then AI)
                var invoiceData = await _processor.ProcessAnyInvoice(invoicePath);

                // Ensure we have minimum required fields before proceeding
                if (ValidateInvoiceData(invoiceData))
                {
                    // Send to accounting system (QuickBooks, Xero, etc.)
                    await SaveToAccountingSystem(invoiceData);

                    // Archive successful invoices
                    string destPath = Path.Combine(_processedFolder, fileName);
                    File.Move(invoicePath, destPath, overwrite: true);

                    results.Add(new ProcessingResult
                    {
                        FileName = fileName,
                        Success = true,
                        InvoiceNumber = invoiceData.InvoiceNumber
                    });

                    Console.WriteLine($"✓ Processed: {invoiceData.InvoiceNumber}");
                }
                else
                {
                    throw new Exception("Validation failed - missing required fields");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"✗ Failed: {fileName} - {ex.Message}");

                // Quarantine failed invoices for manual review
                string destPath = Path.Combine(_errorFolder, fileName);
                File.Move(invoicePath, destPath, overwrite: true);

                results.Add(new ProcessingResult
                {
                    FileName = fileName,
                    Success = false,
                    ErrorMessage = ex.Message
                });
            }
        }

        GenerateReport(results);
        return results;
    }

    // Checks for minimum required fields
    private bool ValidateInvoiceData(InvoiceData data)
    {
        return !string.IsNullOrEmpty(data.InvoiceNumber) &&
               !string.IsNullOrEmpty(data.VendorName) &&
               data.TotalAmount > 0;
    }

    // Placeholder for accounting system integration
    private async Task SaveToAccountingSystem(InvoiceData data)
    {
        // Integrate with your accounting system here
        // Examples: QuickBooks API, Xero API, SAP, or database storage
        Console.WriteLine($"  Saved invoice {data.InvoiceNumber} to accounting system");
        await Task.CompletedTask;
    }

    // Outputs a summary of the batch processing results
    private void GenerateReport(List<ProcessingResult> results)
    {
        int successful = results.Count(r => r.Success);
        int failed = results.Count(r => !r.Success);

        Console.WriteLine($"\n========== Processing Complete ==========");
        Console.WriteLine($"Total Processed: {results.Count}");
        Console.WriteLine($"Successful: {successful}");
        Console.WriteLine($"Failed: {failed}");

        if (failed > 0)
        {
            Console.WriteLine("\nFailed invoices requiring review:");
            foreach (var failure in results.Where(r => !r.Success))
            {
                Console.WriteLine($"  • {failure.FileName}: {failure.ErrorMessage}");
            }
        }
    }
}
Imports IronPdf
Imports System
Imports System.IO
Imports System.Threading.Tasks
Imports System.Collections.Generic
Imports System.Linq

' Tracks the outcome of processing each invoice
Public Class ProcessingResult
    Public Property FileName As String
    Public Property Success As Boolean
    Public Property InvoiceNumber As String
    Public Property ErrorMessage As String
End Class

' Complete automation pipeline for accounts payable
' Watches a folder, extracts data, validates, and routes to accounting system
Public Class InvoiceAutomationPipeline
    Private ReadOnly _processor As SmartInvoiceProcessor
    Private ReadOnly _inputFolder As String
    Private ReadOnly _processedFolder As String
    Private ReadOnly _errorFolder As String

    Public Sub New(apiKey As String, inputFolder As String)
        _processor = New SmartInvoiceProcessor(apiKey)
        _inputFolder = inputFolder
        _processedFolder = Path.Combine(inputFolder, "processed")
        _errorFolder = Path.Combine(inputFolder, "errors")

        ' Create output directories if they don't exist
        Directory.CreateDirectory(_processedFolder)
        Directory.CreateDirectory(_errorFolder)
    End Sub

    ' Main entry point - processes all PDFs in the input folder
    Public Async Function ProcessInvoiceBatch() As Task(Of List(Of ProcessingResult))
        Dim invoiceFiles As String() = Directory.GetFiles(_inputFolder, "*.pdf")
        Console.WriteLine($"Found {invoiceFiles.Length} invoices to process")

        Dim results As New List(Of ProcessingResult)()

        For Each invoicePath As String In invoiceFiles
            Dim fileName As String = Path.GetFileName(invoicePath)

            Try
                Console.WriteLine($"Processing: {fileName}")

                ' Extract data using smart processor (patterns first, then AI)
                Dim invoiceData = Await _processor.ProcessAnyInvoice(invoicePath)

                ' Ensure we have minimum required fields before proceeding
                If ValidateInvoiceData(invoiceData) Then
                    ' Send to accounting system (QuickBooks, Xero, etc.)
                    Await SaveToAccountingSystem(invoiceData)

                    ' Archive successful invoices
                    Dim destPath As String = Path.Combine(_processedFolder, fileName)
                    File.Move(invoicePath, destPath, overwrite:=True)

                    results.Add(New ProcessingResult With {
                        .FileName = fileName,
                        .Success = True,
                        .InvoiceNumber = invoiceData.InvoiceNumber
                    })

                    Console.WriteLine($"✓ Processed: {invoiceData.InvoiceNumber}")
                Else
                    Throw New Exception("Validation failed - missing required fields")
                End If
            Catch ex As Exception
                Console.WriteLine($"✗ Failed: {fileName} - {ex.Message}")

                ' Quarantine failed invoices for manual review
                Dim destPath As String = Path.Combine(_errorFolder, fileName)
                File.Move(invoicePath, destPath, overwrite:=True)

                results.Add(New ProcessingResult With {
                    .FileName = fileName,
                    .Success = False,
                    .ErrorMessage = ex.Message
                })
            End Try
        Next

        GenerateReport(results)
        Return results
    End Function

    ' Checks for minimum required fields
    Private Function ValidateInvoiceData(data As InvoiceData) As Boolean
        Return Not String.IsNullOrEmpty(data.InvoiceNumber) AndAlso
               Not String.IsNullOrEmpty(data.VendorName) AndAlso
               data.TotalAmount > 0
    End Function

    ' Placeholder for accounting system integration
    Private Async Function SaveToAccountingSystem(data As InvoiceData) As Task
        ' Integrate with your accounting system here
        ' Examples: QuickBooks API, Xero API, SAP, or database storage
        Console.WriteLine($"  Saved invoice {data.InvoiceNumber} to accounting system")
        Await Task.CompletedTask
    End Function

    ' Outputs a summary of the batch processing results
    Private Sub GenerateReport(results As List(Of ProcessingResult))
        Dim successful As Integer = results.Count(Function(r) r.Success)
        Dim failed As Integer = results.Count(Function(r) Not r.Success)

        Console.WriteLine(vbCrLf & "========== Processing Complete ==========")
        Console.WriteLine($"Total Processed: {results.Count}")
        Console.WriteLine($"Successful: {successful}")
        Console.WriteLine($"Failed: {failed}")

        If failed > 0 Then
            Console.WriteLine(vbCrLf & "Failed invoices requiring review:")
            For Each failure In results.Where(Function(r) Not r.Success)
                Console.WriteLine($"  • {failure.FileName}: {failure.ErrorMessage}")
            Next
        End If
    End Sub
End Class
$vbLabelText   $csharpLabel

该流水线实现了一个完整的工作流程：它会扫描文件夹中传入的 PDF 文件，处理每一个文件，验证提取的数据，将成功提取的数据传输到您的会计系统，并将失败的数据隔离以便进行人工审核。 摘要报告可提供处理结果的可见性。

如何将 C## 发票处理与会计系统集成

提取的发票数据最终需要流入会计系统，用于支付和记录。 具体内容因平台而异，但集成模式是一致的。

QuickBooks、Xero 和 SAP 的常见集成模式有哪些？

大多数会计平台都提供 REST API，用于以编程方式创建账单或发票。 以下是一种通用模式，您可以根据具体平台进行调整：

using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

// Generic integration layer for pushing invoice data to accounting systems
// Adapt the API calls based on your specific platform
public class AccountingSystemIntegration
{
    private readonly HttpClient _httpClient;
    private readonly string _apiKey;
    private readonly string _baseUrl;

    public AccountingSystemIntegration(string apiKey, string baseUrl)
    {
        _apiKey = apiKey;
        _baseUrl = baseUrl;
        _httpClient = new HttpClient();
        _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_apiKey}");
    }

    // Creates a Bill in QuickBooks (vendor invoices are called "Bills")
    public async Task SendToQuickBooks(InvoiceData invoice)
    {
        // QuickBooks Bill structure - see their API docs for full schema
        var bill = new
        {
            VendorRef = new { name = invoice.VendorName },
            TxnDate = invoice.InvoiceDate,
            DocNumber = invoice.InvoiceNumber,
            TotalAmt = invoice.TotalAmount,
            Line = new[]
            {
                new
                {
                    Amount = invoice.TotalAmount,
                    DetailType = "AccountBasedExpenseLineDetail",
                    AccountBasedExpenseLineDetail = new
                    {
                        AccountRef = new { name = "Accounts Payable" }
                    }
                }
            }
        };

        await PostToApi("/v3/company/{companyId}/bill", bill);
    }

    // Creates an accounts payable invoice in Xero
    public async Task SendToXero(InvoiceData invoice)
    {
        // ACCPAY type indicates this is a bill to pay (not a sales invoice)
        var bill = new
        {
            Type = "ACCPAY",
            Contact = new { Name = invoice.VendorName },
            Date = invoice.InvoiceDate,
            InvoiceNumber = invoice.InvoiceNumber,
            Total = invoice.TotalAmount
        };

        await PostToApi("/api.xro/2.0/Invoices", bill);
    }

    // Generic POST helper with error handling
    private async Task PostToApi(string endpoint, object payload)
    {
        string json = JsonSerializer.Serialize(payload);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        var response = await _httpClient.PostAsync($"{_baseUrl}{endpoint}", content);

        if (!response.IsSuccessStatusCode)
        {
            string error = await response.Content.ReadAsStringAsync();
            throw new Exception($"API Error: {response.StatusCode} - {error}");
        }

        Console.WriteLine($"Successfully posted to {endpoint}");
    }
}
using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

// Generic integration layer for pushing invoice data to accounting systems
// Adapt the API calls based on your specific platform
public class AccountingSystemIntegration
{
    private readonly HttpClient _httpClient;
    private readonly string _apiKey;
    private readonly string _baseUrl;

    public AccountingSystemIntegration(string apiKey, string baseUrl)
    {
        _apiKey = apiKey;
        _baseUrl = baseUrl;
        _httpClient = new HttpClient();
        _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_apiKey}");
    }

    // Creates a Bill in QuickBooks (vendor invoices are called "Bills")
    public async Task SendToQuickBooks(InvoiceData invoice)
    {
        // QuickBooks Bill structure - see their API docs for full schema
        var bill = new
        {
            VendorRef = new { name = invoice.VendorName },
            TxnDate = invoice.InvoiceDate,
            DocNumber = invoice.InvoiceNumber,
            TotalAmt = invoice.TotalAmount,
            Line = new[]
            {
                new
                {
                    Amount = invoice.TotalAmount,
                    DetailType = "AccountBasedExpenseLineDetail",
                    AccountBasedExpenseLineDetail = new
                    {
                        AccountRef = new { name = "Accounts Payable" }
                    }
                }
            }
        };

        await PostToApi("/v3/company/{companyId}/bill", bill);
    }

    // Creates an accounts payable invoice in Xero
    public async Task SendToXero(InvoiceData invoice)
    {
        // ACCPAY type indicates this is a bill to pay (not a sales invoice)
        var bill = new
        {
            Type = "ACCPAY",
            Contact = new { Name = invoice.VendorName },
            Date = invoice.InvoiceDate,
            InvoiceNumber = invoice.InvoiceNumber,
            Total = invoice.TotalAmount
        };

        await PostToApi("/api.xro/2.0/Invoices", bill);
    }

    // Generic POST helper with error handling
    private async Task PostToApi(string endpoint, object payload)
    {
        string json = JsonSerializer.Serialize(payload);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        var response = await _httpClient.PostAsync($"{_baseUrl}{endpoint}", content);

        if (!response.IsSuccessStatusCode)
        {
            string error = await response.Content.ReadAsStringAsync();
            throw new Exception($"API Error: {response.StatusCode} - {error}");
        }

        Console.WriteLine($"Successfully posted to {endpoint}");
    }
}
Imports System
Imports System.Net.Http
Imports System.Text
Imports System.Text.Json
Imports System.Threading.Tasks

' Generic integration layer for pushing invoice data to accounting systems
' Adapt the API calls based on your specific platform
Public Class AccountingSystemIntegration
    Private ReadOnly _httpClient As HttpClient
    Private ReadOnly _apiKey As String
    Private ReadOnly _baseUrl As String

    Public Sub New(apiKey As String, baseUrl As String)
        _apiKey = apiKey
        _baseUrl = baseUrl
        _httpClient = New HttpClient()
        _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_apiKey}")
    End Sub

    ' Creates a Bill in QuickBooks (vendor invoices are called "Bills")
    Public Async Function SendToQuickBooks(invoice As InvoiceData) As Task
        ' QuickBooks Bill structure - see their API docs for full schema
        Dim bill = New With {
            .VendorRef = New With {.name = invoice.VendorName},
            .TxnDate = invoice.InvoiceDate,
            .DocNumber = invoice.InvoiceNumber,
            .TotalAmt = invoice.TotalAmount,
            .Line = New Object() {
                New With {
                    .Amount = invoice.TotalAmount,
                    .DetailType = "AccountBasedExpenseLineDetail",
                    .AccountBasedExpenseLineDetail = New With {
                        .AccountRef = New With {.name = "Accounts Payable"}
                    }
                }
            }
        }

        Await PostToApi("/v3/company/{companyId}/bill", bill)
    End Function

    ' Creates an accounts payable invoice in Xero
    Public Async Function SendToXero(invoice As InvoiceData) As Task
        ' ACCPAY type indicates this is a bill to pay (not a sales invoice)
        Dim bill = New With {
            .Type = "ACCPAY",
            .Contact = New With {.Name = invoice.VendorName},
            .Date = invoice.InvoiceDate,
            .InvoiceNumber = invoice.InvoiceNumber,
            .Total = invoice.TotalAmount
        }

        Await PostToApi("/api.xro/2.0/Invoices", bill)
    End Function

    ' Generic POST helper with error handling
    Private Async Function PostToApi(endpoint As String, payload As Object) As Task
        Dim json As String = JsonSerializer.Serialize(payload)
        Dim content = New StringContent(json, Encoding.UTF8, "application/json")

        Dim response = Await _httpClient.PostAsync($"{_baseUrl}{endpoint}", content)

        If Not response.IsSuccessStatusCode Then
            Dim error As String = Await response.Content.ReadAsStringAsync()
            Throw New Exception($"API Error: {response.StatusCode} - {error}")
        End If

        Console.WriteLine($"Successfully posted to {endpoint}")
    End Function
End Class
$vbLabelText   $csharpLabel

每个平台都有自己的验证机制（QuickBooks 和 Xero 使用 OAuth，SAP 使用各种方法）、必填字段和 API 约定。 具体细节请参考目标平台的文档，但将提取的发票数据转换为 API 有效载荷的模式保持一致。

如何批量处理数百份发票

大批量的发票处理需要仔细关注并发性和资源管理。 下面是一种使用并行处理和受控并发的模式：

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

// Tracks the result of processing a single invoice in a batch
public class BatchResult
{
    public string FilePath { get; set; }
    public bool Success { get; set; }
    public string InvoiceNumber { get; set; }
    public string Error { get; set; }
}

// High-volume invoice processor with controlled parallelism
// Prevents overwhelming APIs while maximizing throughput
public class BatchInvoiceProcessor
{
    private readonly SmartInvoiceProcessor _invoiceProcessor;
    private readonly AccountingSystemIntegration _accountingIntegration;
    private readonly int _maxConcurrency;

    public BatchInvoiceProcessor(string aiApiKey, string accountingApiKey,
        string accountingUrl, int maxConcurrency = 5)
    {
        _invoiceProcessor = new SmartInvoiceProcessor(aiApiKey);
        _accountingIntegration = new AccountingSystemIntegration(accountingApiKey, accountingUrl);
        _maxConcurrency = maxConcurrency;  // Adjust based on API rate limits
    }

    // Processes multiple invoices in parallel with controlled concurrency
    public async Task<List<BatchResult>> ProcessInvoiceBatch(List<string> invoicePaths)
    {
        // Thread-safe collection for gathering results from parallel tasks
        var results = new ConcurrentBag<BatchResult>();

        // Semaphore limits how many invoices process simultaneously
        var semaphore = new SemaphoreSlim(_maxConcurrency);

        // Create a task for each invoice
        var tasks = invoicePaths.Select(async path =>
        {
            // Wait for a slot to become available
            await semaphore.WaitAsync();
            try
            {
                var result = await ProcessSingleInvoice(path);
                results.Add(result);
            }
            finally
            {
                // Release slot for next invoice
                semaphore.Release();
            }
        });

        // Wait for all invoices to complete
        await Task.WhenAll(tasks);

        // Output summary statistics
        var resultList = results.ToList();
        int successful = resultList.Count(r => r.Success);
        int failed = resultList.Count(r => !r.Success);

        Console.WriteLine($"\nBatch Processing Complete:");
        Console.WriteLine($"  Total: {resultList.Count}");
        Console.WriteLine($"  Successful: {successful}");
        Console.WriteLine($"  Failed: {failed}");

        return resultList;
    }

    // Processes one invoice: extract data and send to accounting system
    private async Task<BatchResult> ProcessSingleInvoice(string pdfPath)
    {
        try
        {
            Console.WriteLine($"Processing: {pdfPath}");

            var invoiceData = await _invoiceProcessor.ProcessAnyInvoice(pdfPath);
            await _accountingIntegration.SendToQuickBooks(invoiceData);

            Console.WriteLine($"✓ Completed: {invoiceData.InvoiceNumber}");

            return new BatchResult
            {
                FilePath = pdfPath,
                Success = true,
                InvoiceNumber = invoiceData.InvoiceNumber
            };
        }
        catch (Exception ex)
        {
            Console.WriteLine($"✗ Failed: {pdfPath}");

            return new BatchResult
            {
                FilePath = pdfPath,
                Success = false,
                Error = ex.Message
            };
        }
    }
}
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

// Tracks the result of processing a single invoice in a batch
public class BatchResult
{
    public string FilePath { get; set; }
    public bool Success { get; set; }
    public string InvoiceNumber { get; set; }
    public string Error { get; set; }
}

// High-volume invoice processor with controlled parallelism
// Prevents overwhelming APIs while maximizing throughput
public class BatchInvoiceProcessor
{
    private readonly SmartInvoiceProcessor _invoiceProcessor;
    private readonly AccountingSystemIntegration _accountingIntegration;
    private readonly int _maxConcurrency;

    public BatchInvoiceProcessor(string aiApiKey, string accountingApiKey,
        string accountingUrl, int maxConcurrency = 5)
    {
        _invoiceProcessor = new SmartInvoiceProcessor(aiApiKey);
        _accountingIntegration = new AccountingSystemIntegration(accountingApiKey, accountingUrl);
        _maxConcurrency = maxConcurrency;  // Adjust based on API rate limits
    }

    // Processes multiple invoices in parallel with controlled concurrency
    public async Task<List<BatchResult>> ProcessInvoiceBatch(List<string> invoicePaths)
    {
        // Thread-safe collection for gathering results from parallel tasks
        var results = new ConcurrentBag<BatchResult>();

        // Semaphore limits how many invoices process simultaneously
        var semaphore = new SemaphoreSlim(_maxConcurrency);

        // Create a task for each invoice
        var tasks = invoicePaths.Select(async path =>
        {
            // Wait for a slot to become available
            await semaphore.WaitAsync();
            try
            {
                var result = await ProcessSingleInvoice(path);
                results.Add(result);
            }
            finally
            {
                // Release slot for next invoice
                semaphore.Release();
            }
        });

        // Wait for all invoices to complete
        await Task.WhenAll(tasks);

        // Output summary statistics
        var resultList = results.ToList();
        int successful = resultList.Count(r => r.Success);
        int failed = resultList.Count(r => !r.Success);

        Console.WriteLine($"\nBatch Processing Complete:");
        Console.WriteLine($"  Total: {resultList.Count}");
        Console.WriteLine($"  Successful: {successful}");
        Console.WriteLine($"  Failed: {failed}");

        return resultList;
    }

    // Processes one invoice: extract data and send to accounting system
    private async Task<BatchResult> ProcessSingleInvoice(string pdfPath)
    {
        try
        {
            Console.WriteLine($"Processing: {pdfPath}");

            var invoiceData = await _invoiceProcessor.ProcessAnyInvoice(pdfPath);
            await _accountingIntegration.SendToQuickBooks(invoiceData);

            Console.WriteLine($"✓ Completed: {invoiceData.InvoiceNumber}");

            return new BatchResult
            {
                FilePath = pdfPath,
                Success = true,
                InvoiceNumber = invoiceData.InvoiceNumber
            };
        }
        catch (Exception ex)
        {
            Console.WriteLine($"✗ Failed: {pdfPath}");

            return new BatchResult
            {
                FilePath = pdfPath,
                Success = false,
                Error = ex.Message
            };
        }
    }
}
Imports System
Imports System.Collections.Concurrent
Imports System.Collections.Generic
Imports System.Linq
Imports System.Threading
Imports System.Threading.Tasks

' Tracks the result of processing a single invoice in a batch
Public Class BatchResult
    Public Property FilePath As String
    Public Property Success As Boolean
    Public Property InvoiceNumber As String
    Public Property Error As String
End Class

' High-volume invoice processor with controlled parallelism
' Prevents overwhelming APIs while maximizing throughput
Public Class BatchInvoiceProcessor
    Private ReadOnly _invoiceProcessor As SmartInvoiceProcessor
    Private ReadOnly _accountingIntegration As AccountingSystemIntegration
    Private ReadOnly _maxConcurrency As Integer

    Public Sub New(aiApiKey As String, accountingApiKey As String, accountingUrl As String, Optional maxConcurrency As Integer = 5)
        _invoiceProcessor = New SmartInvoiceProcessor(aiApiKey)
        _accountingIntegration = New AccountingSystemIntegration(accountingApiKey, accountingUrl)
        _maxConcurrency = maxConcurrency ' Adjust based on API rate limits
    End Sub

    ' Processes multiple invoices in parallel with controlled concurrency
    Public Async Function ProcessInvoiceBatch(invoicePaths As List(Of String)) As Task(Of List(Of BatchResult))
        ' Thread-safe collection for gathering results from parallel tasks
        Dim results = New ConcurrentBag(Of BatchResult)()

        ' Semaphore limits how many invoices process simultaneously
        Dim semaphore = New SemaphoreSlim(_maxConcurrency)

        ' Create a task for each invoice
        Dim tasks = invoicePaths.Select(Async Function(path)
                                            ' Wait for a slot to become available
                                            Await semaphore.WaitAsync()
                                            Try
                                                Dim result = Await ProcessSingleInvoice(path)
                                                results.Add(result)
                                            Finally
                                                ' Release slot for next invoice
                                                semaphore.Release()
                                            End Try
                                        End Function)

        ' Wait for all invoices to complete
        Await Task.WhenAll(tasks)

        ' Output summary statistics
        Dim resultList = results.ToList()
        Dim successful = resultList.Count(Function(r) r.Success)
        Dim failed = resultList.Count(Function(r) Not r.Success)

        Console.WriteLine(vbCrLf & "Batch Processing Complete:")
        Console.WriteLine($"  Total: {resultList.Count}")
        Console.WriteLine($"  Successful: {successful}")
        Console.WriteLine($"  Failed: {failed}")

        Return resultList
    End Function

    ' Processes one invoice: extract data and send to accounting system
    Private Async Function ProcessSingleInvoice(pdfPath As String) As Task(Of BatchResult)
        Try
            Console.WriteLine($"Processing: {pdfPath}")

            Dim invoiceData = Await _invoiceProcessor.ProcessAnyInvoice(pdfPath)
            Await _accountingIntegration.SendToQuickBooks(invoiceData)

            Console.WriteLine($"✓ Completed: {invoiceData.InvoiceNumber}")

            Return New BatchResult With {
                .FilePath = pdfPath,
                .Success = True,
                .InvoiceNumber = invoiceData.InvoiceNumber
            }
        Catch ex As Exception
            Console.WriteLine($"✗ Failed: {pdfPath}")

            Return New BatchResult With {
                .FilePath = pdfPath,
                .Success = False,
                .Error = ex.Message
            }
        End Try
    End Function
End Class
$vbLabelText   $csharpLabel

SemaphoreSlim可确保您不会淹没外部 API 或耗尽系统资源。 根据您的 API 速率限制和服务器容量调整 _maxConcurrency 。 ConcurrentBag 可以安全地收集并行操作的结果。

下一步

发票自动化是减少人工工作、减少错误和加快业务流程的重要机会。 本指南将引导您了解整个生命周期：从 HTML 模板生成专业发票，符合 ZUGFeRD 和 Factur-X 电子发票标准、使用模式匹配和AI 驱动的处理从收到的发票中提取数据，并构建可扩展的自动化管道。

IronPDF是这些功能的基础，它提供了强大的 HTML 到 PDF 渲染功能、可靠的 文本提取功能以及 PDF/A-3 电子发票合规性所需的附件功能。 其基于 Chrome 浏览器的渲染引擎可确保您的发票看起来与设计完全一致，而其提取方法可自动处理 PDF 文本编码的复杂性。

此处显示的模式是起点。 实际实施时需要根据您的具体发票格式、会计系统和业务规则进行调整。 对于大容量场景，批处理教程涵盖了并行执行与受控并发和错误恢复。

准备好开始构建了吗？ 下载 IronPDF 并免费试用。 该库包含一个免费的开发许可证，因此您可以在获得生产许可证之前充分评估发票生成、数据提取和PDF 报告功能。 如果您对发票自动化或会计系统集成有任何疑问，请联系我们的工程支持团队。

常见问题解答

IronPDF 在 C# 发票处理中的用途是什么？

IronPDF 用于 C# 发票处理，可生成专业的 PDF 发票、提取结构化数据并自动执行发票工作流程，同时确保符合 ZUGFeRD 和 Factur-X 等标准。

如何在 C# 中使用 IronPDF 生成 PDF 发票？

通过利用 IronPDF 的 API 以编程方式创建和自定义 PDF 文档，您可以使用 IronPDF 在 C# 中生成 PDF 发票。这包括添加构成发票的文本、表格和图片等元素。

什么是 ZUGFeRD 和 Factur-X，IronPDF 如何支持它们？

ZUGFeRD 和 Factur-X 是电子发票标准，可确保发票的人机可读性。IronPDF 支持这些标准，允许您生成符合这些规范的 PDF 发票。

IronPdf 如何帮助实现应付账款流程自动化？

IronPdf 可以从发票中提取结构化数据并与自动化管道集成，从而实现应付账款流程的自动化，减少人工数据录入并提高效率。

IronPDF 能否从现有的 PDF 发票中提取数据？

是的，IronPDF 可以从现有的 PDF 发票中提取结构化数据，从而更容易自动处理和分析发票信息。

使用 IronPDF 在 C# 中处理发票有什么好处？

使用 IronPdf 在 C# 中处理发票的好处包括：简化发票生成、符合国际发票标准、高效提取数据以及增强自动化功能。

是否可以使用 IronPDF 自定义 PDF 发票的外观？

是的，IronPDF 允许您通过添加各种设计元素（如徽标、文本格式和布局调整）自定义 PDF 发票的外观，以满足品牌推广的要求。

使用 IronPdf 自动处理发票的典型步骤是什么？

要使用 IronPdf 自动处理发票，通常需要生成发票、提取必要的数据，并与其他系统或自动化工具集成以简化工作流程。

IronPdf 如何处理不同的发票格式？

IronPDF 可通过提供生成、处理和读取 PDF 文档的工具来处理各种发票格式，确保与常见的电子发票标准兼容。

Curtis Chau
Curtis Chau
  立即与工程团队聊天
技术作家

Curtis Chau 拥有卡尔顿大学的计算机科学学士学位，专注于前端开发，精通 Node.js、TypeScript、JavaScript 和 React。他热衷于打造直观且美观的用户界面，喜欢使用现代框架并创建结构良好、视觉吸引力强的手册。

除了开发之外，Curtis 对物联网 (IoT) 有浓厚的兴趣，探索将硬件和软件集成的新方法。在空闲时间，他喜欢玩游戏和构建 Discord 机器人，将他对技术的热爱与创造力相结合。

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