在 C# 中以HTML轉PDF方式生成報表（替代 Crystal Reports，支援 .NET 10）

using IronPdf;

// Service class for generating invoice PDFs from Razor views
public class InvoiceReportService
{
    private readonly IRazorViewEngine _razorViewEngine;
    private readonly ITempDataProvider _tempDataProvider;
    private readonly IServiceProvider _serviceProvider;

    public InvoiceReportService(
        IRazorViewEngine razorViewEngine,
        ITempDataProvider tempDataProvider,
        IServiceProvider serviceProvider)
    {
        _razorViewEngine = razorViewEngine;
        _tempDataProvider = tempDataProvider;
        _serviceProvider = serviceProvider;
    }

    // Generate PDF from invoice model
    public async Task<byte[]> GenerateInvoicePdfAsync(InvoiceModel invoice)
    {
        // Render Razor view to HTML string
        string html = await RenderViewToStringAsync("InvoiceTemplate", invoice);

        // Configure PDF renderer with margins and paper size
        var renderer = new ChromePdfRenderer();
        renderer.RenderingOptions.MarginTop = 10;
        renderer.RenderingOptions.MarginBottom = 10;
        renderer.RenderingOptions.MarginLeft = 10;
        renderer.RenderingOptions.MarginRight = 10;
        renderer.RenderingOptions.PaperSize = IronPdf.Rendering.PdfPaperSize.Letter;

        // Convert HTML to PDF and return bytes
        var pdfDocument = renderer.RenderHtmlAsPdf(html);
        return pdfDocument.BinaryData;
    }

    // Helper method to render a Razor view to string
    private async Task<string> RenderViewToStringAsync<TModel>(string viewName, TModel model)
    {
        var httpContext = new DefaultHttpContext { RequestServices = _serviceProvider };
        var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());

        using var stringWriter = new StringWriter();
        var viewResult = _razorViewEngine.FindView(actionContext, viewName, false);

        if (!viewResult.Success)
            throw new InvalidOperationException($"View '{viewName}' not found.");

        var viewDictionary = new ViewDataDictionary<TModel>(
            new EmptyModelMetadataProvider(), new ModelStateDictionary()) { Model = model };

        var viewContext = new ViewContext(actionContext, viewResult.View, viewDictionary,
            new TempDataDictionary(actionContext.HttpContext, _tempDataProvider),
            stringWriter, new HtmlHelperOptions());

        await viewResult.View.RenderAsync(viewContext);
        return stringWriter.ToString();
    }
}

Imports IronPdf
Imports Microsoft.AspNetCore.Mvc.Razor
Imports Microsoft.AspNetCore.Mvc.ViewFeatures
Imports Microsoft.Extensions.DependencyInjection
Imports Microsoft.AspNetCore.Http
Imports Microsoft.AspNetCore.Mvc
Imports Microsoft.AspNetCore.Routing
Imports System.IO
Imports System.Threading.Tasks

' Service class for generating invoice PDFs from Razor views
Public Class InvoiceReportService
    Private ReadOnly _razorViewEngine As IRazorViewEngine
    Private ReadOnly _tempDataProvider As ITempDataProvider
    Private ReadOnly _serviceProvider As IServiceProvider

    Public Sub New(razorViewEngine As IRazorViewEngine, tempDataProvider As ITempDataProvider, serviceProvider As IServiceProvider)
        _razorViewEngine = razorViewEngine
        _tempDataProvider = tempDataProvider
        _serviceProvider = serviceProvider
    End Sub

    ' Generate PDF from invoice model
    Public Async Function GenerateInvoicePdfAsync(invoice As InvoiceModel) As Task(Of Byte())
        ' Render Razor view to HTML string
        Dim html As String = Await RenderViewToStringAsync("InvoiceTemplate", invoice)

        ' Configure PDF renderer with margins and paper size
        Dim renderer As New ChromePdfRenderer()
        renderer.RenderingOptions.MarginTop = 10
        renderer.RenderingOptions.MarginBottom = 10
        renderer.RenderingOptions.MarginLeft = 10
        renderer.RenderingOptions.MarginRight = 10
        renderer.RenderingOptions.PaperSize = IronPdf.Rendering.PdfPaperSize.Letter

        ' Convert HTML to PDF and return bytes
        Dim pdfDocument = renderer.RenderHtmlAsPdf(html)
        Return pdfDocument.BinaryData
    End Function

    ' Helper method to render a Razor view to string
    Private Async Function RenderViewToStringAsync(Of TModel)(viewName As String, model As TModel) As Task(Of String)
        Dim httpContext As New DefaultHttpContext With {.RequestServices = _serviceProvider}
        Dim actionContext As New ActionContext(httpContext, New RouteData(), New ActionDescriptor())

        Using stringWriter As New StringWriter()
            Dim viewResult = _razorViewEngine.FindView(actionContext, viewName, False)

            If Not viewResult.Success Then
                Throw New InvalidOperationException($"View '{viewName}' not found.")
            End If

            Dim viewDictionary As New ViewDataDictionary(Of TModel)(
                New EmptyModelMetadataProvider(), New ModelStateDictionary()) With {.Model = model}

            Dim viewContext As New ViewContext(actionContext, viewResult.View, viewDictionary,
                New TempDataDictionary(actionContext.HttpContext, _tempDataProvider),
                stringWriter, New HtmlHelperOptions())

            Await viewResult.View.RenderAsync(viewContext)
            Return stringWriter.ToString()
        End Using
    End Function
End Class

using IronPdf;
using IronSoftware.Drawing;

// Configure text-based headers and footers
var renderer = new ChromePdfRenderer();

// Set starting page number
renderer.RenderingOptions.FirstPageNumber = 1;

// Add centered header with divider line
renderer.RenderingOptions.TextHeader = new TextHeaderFooter
{
    CenterText = "CONFIDENTIAL - Internal Use Only",
    DrawDividerLine = true,
    Font = FontTypes.Arial,
    FontSize = 10
};

// Add footer with date on left, page numbers on right
renderer.RenderingOptions.TextFooter = new TextHeaderFooter
{
    LeftText = "{date} {time}",
    RightText = "Page {page} of {total-pages}",
    DrawDividerLine = true,
    Font = FontTypes.Arial,
    FontSize = 9
};

// Set margins to accommodate header/footer
renderer.RenderingOptions.MarginTop = 25;
renderer.RenderingOptions.MarginBottom = 20;

Imports IronPdf
Imports IronSoftware.Drawing

' Configure text-based headers and footers
Dim renderer As New ChromePdfRenderer()

' Set starting page number
renderer.RenderingOptions.FirstPageNumber = 1

' Add centered header with divider line
renderer.RenderingOptions.TextHeader = New TextHeaderFooter With {
    .CenterText = "CONFIDENTIAL - Internal Use Only",
    .DrawDividerLine = True,
    .Font = FontTypes.Arial,
    .FontSize = 10
}

' Add footer with date on left, page numbers on right
renderer.RenderingOptions.TextFooter = New TextHeaderFooter With {
    .LeftText = "{date} {time}",
    .RightText = "Page {page} of {total-pages}",
    .DrawDividerLine = True,
    .Font = FontTypes.Arial,
    .FontSize = 9
}

' Set margins to accommodate header/footer
renderer.RenderingOptions.MarginTop = 25
renderer.RenderingOptions.MarginBottom = 20

using IronPdf;
using System;

var renderer = new ChromePdfRenderer();

// Configure HTML header with logo and custom layout
renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter
{
    MaxHeight = 30,
    HtmlFragment = @"
<div style='display: flex; justify-content: space-between; align-items: center;
            width: 100%; font-family: Arial; font-size: 10px; color: #666;'>
    <img src='logo.png' style='height: 25px;'>
    <span>Company Name Inc.</span>
    <span>Invoice Report</span>
</div>",
    BaseUrl = new Uri(@"C:\assets\images\").AbsoluteUri
};

// Configure HTML footer with page info and generation date
renderer.RenderingOptions.HtmlFooter = new HtmlHeaderFooter
{
    MaxHeight = 20,
    HtmlFragment = @"
<div style='text-align: center; font-size: 9px; color: #999;
            border-top: 1px solid #ddd; padding-top: 5px;'>
    Page {page} of {total-pages} | Generated on {date}
</div>",
    DrawDividerLine = false
};

Imports IronPdf
Imports System

Dim renderer As New ChromePdfRenderer()

' Configure HTML header with logo and custom layout
renderer.RenderingOptions.HtmlHeader = New HtmlHeaderFooter With {
    .MaxHeight = 30,
    .HtmlFragment = "
<div style='display: flex; justify-content: space-between; align-items: center;
            width: 100%; font-family: Arial; font-size: 10px; color: #666;'>
    <img src='logo.png' style='height: 25px;'>
    <span>Company Name Inc.</span>
    <span>Invoice Report</span>
</div>",
    .BaseUrl = New Uri("C:\assets\images\").AbsoluteUri
}

' Configure HTML footer with page info and generation date
renderer.RenderingOptions.HtmlFooter = New HtmlHeaderFooter With {
    .MaxHeight = 20,
    .HtmlFragment = "
<div style='text-align: center; font-size: 9px; color: #999;
            border-top: 1px solid #ddd; padding-top: 5px;'>
    Page {page} of {total-pages} | Generated on {date}
</div>",
    .DrawDividerLine = False
}

// Employee directory data models
public class EmployeeDirectoryModel
{
    public List<Department> Departments { get; set; } = new();
    public DateTime GeneratedDate { get; set; } = DateTime.Now;
}

// Department grouping with manager info
public class Department
{
    public string Name { get; set; } = string.Empty;
    public string ManagerName { get; set; } = string.Empty;
    public List<Employee> Employees { get; set; } = new();
}

// Individual employee details
public class Employee
{
    public string Name { get; set; } = string.Empty;
    public string Title { get; set; } = string.Empty;
    public string Email { get; set; } = string.Empty;
    public string Phone { get; set; } = string.Empty;
    public string PhotoUrl { get; set; } = string.Empty;
    public DateTime HireDate { get; set; }
}

' Employee directory data models
Public Class EmployeeDirectoryModel
    Public Property Departments As List(Of Department) = New List(Of Department)()
    Public Property GeneratedDate As DateTime = DateTime.Now
End Class

' Department grouping with manager info
Public Class Department
    Public Property Name As String = String.Empty
    Public Property ManagerName As String = String.Empty
    Public Property Employees As List(Of Employee) = New List(Of Employee)()
End Class

' Individual employee details
Public Class Employee
    Public Property Name As String = String.Empty
    Public Property Title As String = String.Empty
    Public Property Email As String = String.Empty
    Public Property Phone As String = String.Empty
    Public Property PhotoUrl As String = String.Empty
    Public Property HireDate As DateTime
End Class

@model SalesReportModel

<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>

<canvas id="salesChart"></canvas>

<script>
    // Initialize bar chart with data from C# model
    const ctx = document.getElementById('salesChart').getContext('2d');
    new Chart(ctx, {
        type: 'bar',
        data: {
            // Serialize model data to JavaScript arrays
            labels: @Html.Raw(System.Text.Json.JsonSerializer.Serialize(Model.MonthLabels)),
            datasets: [{
                label: 'Monthly Sales',
                data: @Html.Raw(System.Text.Json.JsonSerializer.Serialize(Model.MonthlySales)),
                backgroundColor: 'rgba(52, 152, 219, 0.7)'
            }]
        }
    });
</script>

using IronPdf;

string html = "<h1>Report</h1>";

// Configure renderer to wait for JavaScript execution
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.WaitFor.JavaScript(500); // Wait 500ms for JS to complete
var pdf = renderer.RenderHtmlAsPdf(html);

Imports IronPdf

Dim html As String = "<h1>Report</h1>"

' Configure renderer to wait for JavaScript execution
Dim renderer As New ChromePdfRenderer()
renderer.RenderingOptions.WaitFor.JavaScript(500) ' Wait 500ms for JS to complete
Dim pdf = renderer.RenderHtmlAsPdf(html)

@foreach (var item in Model.Items.OrderBy(x => x.Quantity))
{
    // Apply CSS class based on stock level thresholds
    var rowClass = item.Quantity <= Model.CriticalStockThreshold ? "stock-critical" :
                   item.Quantity <= Model.LowStockThreshold ? "stock-low" : "";

    <tr class="@rowClass">
        <td>@item.SKU</td>
        <td>@item.ProductName</td>
        <td class="text-right">

            <span class="quantity-badge @(item.Quantity <= 5 ? "badge-critical" : "badge-ok")">
                @item.Quantity
            </span>
        </td>
    </tr>
}

using IronPdf;

// Combine multiple reports into a single PDF document
public byte[] GenerateCombinedReport(SalesReportModel sales, InventoryReportModel inventory)
{
    var renderer = new ChromePdfRenderer();

    // Render each report section separately
    var salesPdf = renderer.RenderHtmlAsPdf(RenderSalesReport(sales));
    var inventoryPdf = renderer.RenderHtmlAsPdf(RenderInventoryReport(inventory));

    // Merge PDFs into one document
    var combined = PdfDocument.Merge(salesPdf, inventoryPdf);
    return combined.BinaryData;
}

Imports IronPdf

' Combine multiple reports into a single PDF document
Public Function GenerateCombinedReport(sales As SalesReportModel, inventory As InventoryReportModel) As Byte()
    Dim renderer As New ChromePdfRenderer()

    ' Render each report section separately
    Dim salesPdf = renderer.RenderHtmlAsPdf(RenderSalesReport(sales))
    Dim inventoryPdf = renderer.RenderHtmlAsPdf(RenderInventoryReport(inventory))

    ' Merge PDFs into one document
    Dim combined = PdfDocument.Merge(salesPdf, inventoryPdf)
    Return combined.BinaryData
End Function

using IronPdf;
using System.Collections.Concurrent;

// Generate multiple invoices in parallel using async processing
public async Task<List<ReportResult>> GenerateInvoiceBatchAsync(List<InvoiceModel> invoices)
{
    var results = new ConcurrentBag<ReportResult>();

    // Process invoices concurrently with controlled parallelism
    await Parallel.ForEachAsync(invoices,
        new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount },
        async (invoice, token) =>
        {
            // Each thread gets its own renderer instance
            var renderer = new ChromePdfRenderer();
            string html = BuildInvoiceHtml(invoice);
            var pdf = await renderer.RenderHtmlAsPdfAsync(html);

            // Save individual invoice PDF
            string filename = $"Invoice_{invoice.InvoiceNumber}.pdf";
            await pdf.SaveAsAsync(filename);

            results.Add(new ReportResult { InvoiceNumber = invoice.InvoiceNumber, Success = true });
        });

    return results.ToList();
}

Imports IronPdf
Imports System.Collections.Concurrent
Imports System.Threading.Tasks

' Generate multiple invoices in parallel using async processing
Public Async Function GenerateInvoiceBatchAsync(invoices As List(Of InvoiceModel)) As Task(Of List(Of ReportResult))
    Dim results As New ConcurrentBag(Of ReportResult)()

    ' Process invoices concurrently with controlled parallelism
    Await Task.Run(Async Function()
                       Await Parallel.ForEachAsync(invoices,
                           New ParallelOptions With {.MaxDegreeOfParallelism = Environment.ProcessorCount},
                           Async Function(invoice, token)
                               ' Each thread gets its own renderer instance
                               Dim renderer As New ChromePdfRenderer()
                               Dim html As String = BuildInvoiceHtml(invoice)
                               Dim pdf = Await renderer.RenderHtmlAsPdfAsync(html)

                               ' Save individual invoice PDF
                               Dim filename As String = $"Invoice_{invoice.InvoiceNumber}.pdf"
                               Await pdf.SaveAsAsync(filename)

                               results.Add(New ReportResult With {.InvoiceNumber = invoice.InvoiceNumber, .Success = True})
                           End Function)
                   End Function)

    Return results.ToList()
End Function