C# PDF程式庫

HTML 轉 PDF

using IronPdf;

// Disable local disk access or cross-origin requests
Installation.EnableWebSecurity = true;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Create a PDF from a HTML string using C#
var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");

// Export to a file or Stream
pdf.SaveAs("output.pdf");

// Advanced Example with HTML Assets
// Load external html assets: Images, CSS and JavaScript.
// An optional BasePath 'C:\site\assets\' is set as the file location to load assets from
var myAdvancedPdf = renderer.RenderHtmlAsPdf("<img src='icons/iron.png'>", @"C:\site\assets\");
myAdvancedPdf.SaveAs("html-with-assets.pdf");

using IronPdf;

// Disable local disk access or cross-origin requests
Installation.EnableWebSecurity = true;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Create a PDF from a HTML string using C#
var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");

// Export to a file or Stream
pdf.SaveAs("output.pdf");

// Advanced Example with HTML Assets
// Load external html assets: Images, CSS and JavaScript.
// An optional BasePath 'C:\site\assets\' is set as the file location to load assets from
var myAdvancedPdf = renderer.RenderHtmlAsPdf("<img src='icons/iron.png'>", @"C:\site\assets\");
myAdvancedPdf.SaveAs("html-with-assets.pdf");

PM >Install-Package IronPdf

Install-Package IronPdf

影片

如何使用 WaitFor 來延遲 C# PDF 渲染

Curtis Chau

Updated: 2026年7月19日

從PDFium .NET包轉移到IronPDF，將您的.NET PDF工作流程從一個以渲染為重點的引擎（需要本機二進制依賴）轉變為一個完整的PDF解決方案，能夠處理建立、操作和渲染，並且無需複雜的平臺特定依賴。本指南提供逐步的遷移路徑，消除了本機依賴管理，同時增加了PDFium本身不提供的功能。

為什麼從PDFium包遷移到IronPDF

了解PDFium .NET包

PDFium是Google的BSD-3-Clause C++ PDF渲染和解析引擎—這就是驅動Chrome內建PDF查看器的引擎。沒有由Google提供的官方.NET綁定；相反，.NET生態系統通過社區包消耗PDFium。四個最常被引用的NuGet包是PdfiumViewer（pvginkel； Apache 2.0； 2019年8月存檔，最後一次發布在2017年11月，版本2.13.0，.NET Framework 2.0+），PdfiumViewer.Updated（一個維護的分支，被移植到.NET Core / .NET 6），PDFiumCore（Dtronix； .NET Standard 2.1 P/Invoke綁定），和Pdfium.Net.SDK（Patagames；商業的，永久許可的SDK）。

它們的API不同，但它們共有一個特點：PDFium本身是一個渲染和解析引擎，而不是HTML到PDF或文件創作引擎。PDFium沒有HTML解析器，因此沒有包可以自行將HTML轉換為PDF。本指南使用PdfiumViewer作為"前"片段的代表包，因為其API是最常被引用的；遷移方法對四者來說都是一樣的。

PDFium包的主要限制

渲染為主： PDFium沒有HTML解析器，因此沒有包可以從HTML、URL或任意圖像建立PDF。
開源包的操作有限： PdfiumViewer / PDFiumCore暴露查看和每頁文字抽取；在Patagames Pdfium.Net.SDK中的合併/拆分/表單編輯是部分存在的，而在免費包中基本不存在。
**本機二進制依賴：**需要平台特定的PDFium二進制（pdfium.dll / .so / .dylib）每個RID。
**部署複雜性：**必須按平台捆綁和管理本機二進制，使用x86、x64和運行時資料夾。
基本文字抽取： PdfiumViewer通過GetPdfText(int)暴露每頁的原始文字；布局/格式元資料未暴露。
無HTML到PDF： PDFium沒有HTML解析器；無法直接轉換網頁內容。
**無內建頁首/頁尾：**沒有高階的頁面覆蓋API。
**無內建水印：**沒有蓋章原語。
**表單：**在免費包中為只讀或缺席；在Patagames Pdfium.Net.SDK中可用。
**安全性：**免費包未暴露加密/權限；在Patagames Pdfium.Net.SDK中可用。

PDFium包與IronPDF比較

方面	PDFium .NET包	IronPDF
主要重點	渲染/視覺	完整的PDF解決方案
渲染保真度	高保真渲染	高，特別是對HTML/CSS/JS
從HTML建立PDF	None	是（HTML，網址，圖像）
PDF 操作	免費包：無； Patagames：部分	是（合併，分割，編輯）
HTML 到 PDF	None	是（Chromium引擎）
水印	未內建	是
頁首/頁尾	未內建	是
填寫表單	免費包：無； Patagames：是	是
安全性	免費包：無； Patagames：是	是
本機相依性	必需的	捆綁/ NuGet管理
跨平台	手動本機二進制管理	自動
部署的便利性	由於本機依賴而變得複雜	更簡單；依賴複雜性減少

對於目標現代.NET的團隊，IronPDF提供了一個全面管理的基礎，消除了本機二進制管理，同時增加了全面的PDF建立和操作功能。

開始之前

前提條件

.NET環境：.NET Framework 4.6.2+ 或.NET Core 3.1+ / .NET 5/6/7/8/9+
NuGet存取： 有能力安裝NuGet套件
IronPDF授權： 從ironpdf.com獲取您的授權金鑰

NuGet包變更

# Remove whichever PDFium wrapper you used:
#   PdfiumViewer            (Apache 2.0 - archived 2019, .NET Framework only)
#   PdfiumViewer.Updated    (community fork, .NET Core / .NET 6)
#   PDFiumCore              (Dtronix - .NET Standard 2.1 P/Invoke bindings)
#   Pdfium.Net.SDK          (Patagames - commercial, perpetual license)
dotnet remove package PdfiumViewer
dotnet remove package PdfiumViewer.Updated
dotnet remove package PDFiumCore
dotnet remove package Pdfium.Net.SDK

# Install IronPDF
dotnet add package IronPdf

# Remove whichever PDFium wrapper you used:
#   PdfiumViewer            (Apache 2.0 - archived 2019, .NET Framework only)
#   PdfiumViewer.Updated    (community fork, .NET Core / .NET 6)
#   PDFiumCore              (Dtronix - .NET Standard 2.1 P/Invoke bindings)
#   Pdfium.Net.SDK          (Patagames - commercial, perpetual license)
dotnet remove package PdfiumViewer
dotnet remove package PdfiumViewer.Updated
dotnet remove package PDFiumCore
dotnet remove package Pdfium.Net.SDK

# Install IronPDF
dotnet add package IronPdf

SHELL

授權配置

// Add at application startup (Program.cs or Startup.cs)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

// Add at application startup (Program.cs or Startup.cs)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

' Add at application startup (Program.vb or Startup.vb)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

' Add at application startup (Program.vb or Startup.vb)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

確認PDFium包的使用

# Find PDFium wrapper usage
grep -rE "PdfiumViewer|PDFiumCore|Patagames\.Pdf|PdfDocument\.Load|\.Render\(" --include="*.cs" .

# Find native binary references
grep -rE "pdfium\.dll|libpdfium\.(so|dylib)" --include="*.csproj" --include="*.config" .

# Find platform-specific code
grep -rE "#if.*64|WIN32|WIN64|LINUX|OSX" --include="*.cs" .

# Find PDFium wrapper usage
grep -rE "PdfiumViewer|PDFiumCore|Patagames\.Pdf|PdfDocument\.Load|\.Render\(" --include="*.cs" .

# Find native binary references
grep -rE "pdfium\.dll|libpdfium\.(so|dylib)" --include="*.csproj" --include="*.config" .

# Find platform-specific code
grep -rE "#if.*64|WIN32|WIN64|LINUX|OSX" --include="*.cs" .

SHELL

完整API參考

名稱空間變更

// PDFium wrappers (use the one you installed)
using PdfiumViewer;             // PdfiumViewer / PdfiumViewer.Updated
using PDFiumCore;               // Dtronix PDFiumCore (P/Invoke bindings)
using Patagames.Pdf;            // Patagames Pdfium.Net.SDK
using Patagames.Pdf.Net;        // Patagames Pdfium.Net.SDK

// IronPDF
using IronPdf;
using IronPdf.Rendering;
using IronPdf.Editing;

// PDFium wrappers (use the one you installed)
using PdfiumViewer;             // PdfiumViewer / PdfiumViewer.Updated
using PDFiumCore;               // Dtronix PDFiumCore (P/Invoke bindings)
using Patagames.Pdf;            // Patagames Pdfium.Net.SDK
using Patagames.Pdf.Net;        // Patagames Pdfium.Net.SDK

// IronPDF
using IronPdf;
using IronPdf.Rendering;
using IronPdf.Editing;

Imports PdfiumViewer ' PdfiumViewer / PdfiumViewer.Updated
Imports PDFiumCore ' Dtronix PDFiumCore (P/Invoke bindings)
Imports Patagames.Pdf ' Patagames Pdfium.Net.SDK
Imports Patagames.Pdf.Net ' Patagames Pdfium.Net.SDK

Imports IronPdf
Imports IronPdf.Rendering
Imports IronPdf.Editing

Imports PdfiumViewer ' PdfiumViewer / PdfiumViewer.Updated
Imports PDFiumCore ' Dtronix PDFiumCore (P/Invoke bindings)
Imports Patagames.Pdf ' Patagames Pdfium.Net.SDK
Imports Patagames.Pdf.Net ' Patagames Pdfium.Net.SDK

Imports IronPdf
Imports IronPdf.Rendering
Imports IronPdf.Editing

核心類別映射

PdfiumViewer	IronPDF	注釋
`PdfiumViewer.PdfDocument`	`IronPdf.PdfDocument`	在不同命名空間中同樣的簡單名稱
`PdfRenderer`（WinForms控制）	(不適用)	PdfiumViewer也提供UI控制； IronPDF是無頭的
(不可用)	`ChromePdfRenderer`	HTML / URL → PDF
(不可用)	`HtmlHeaderFooter`	頁首/頁尾

文件載入映射

PdfiumViewer	IronPDF	注釋
`PdfDocument.Load(path)`	`PdfDocument.FromFile(path)`	從檔案載入
`PdfDocument.Load(stream)`	`PdfDocument.FromStream(stream)`	從流載入
(將字節包裹在MemoryStream中)	`PdfDocument.FromBinaryData(bytes)`	從字節載入

文件屬性對應

PdfiumViewer	IronPDF	注釋
`document.PageCount`	`document.PageCount`	一樣
`IList<SizeF>`）	`document.Pages[index].Width / Height`	PdfiumViewer暴露尺寸； pages are not first-class objects
`document.PageSizes[i].Width`	`document.Pages[i].Width`	每頁寬度以點為單位

文字提取映射

PdfiumViewer	IronPDF	注釋
`document.GetPdfText(pageIndex)`	`document.Pages[index].Text`	每頁
(手動迴圈)	`document.ExtractAllText()`	所有頁面

儲存文件映射

PdfiumViewer	IronPDF	注釋
`document.Save(stream)`	`document.SaveAs(path)`	PdfiumViewer需要一個流； IronPDF需要一個路徑
(不可用)	`document.Stream`	存取原始流
(不可用)	`document.BinaryData`	獲取字節

頁面渲染映射

PdfiumViewer	IronPDF	注釋
`document.Render(page, width, height, dpiX, dpiY, flags)`	`pdf.RasterizeToImageFiles(path, DPI)`	光柵化
在`document.Render(i, ...)`上的手動迴圈	`pdf.RasterizeToImageFiles("page_*.png")`	批量渲染所有頁面
手動比例數學	`DPI = 72 * scale`	比例到DPI的轉換

PDFium包中不可用的新功能

IronPDF功能	說明
`ChromePdfRenderer.RenderHtmlAsPdf()`	從HTML建立
`ChromePdfRenderer.RenderUrlAsPdf()`	從URL建立
`ChromePdfRenderer.RenderHtmlFileAsPdf()`	從HTML文件建立
`PdfDocument.Merge()`	合併PDF
`pdf.CopyPages()`	提取頁面
`pdf.RemovePages()`	刪除頁面
`pdf.InsertPdf()`	在位置插入PDF
`pdf.ApplyWatermark()`	新增水印
`pdf.AddHtmlHeaders()`	新增頁首
`pdf.AddHtmlFooters()`	新增頁尾
`pdf.SecuritySettings`	密碼保護
`pdf.SignWithDigitalSignature()`	數位簽名
`pdf.Form`	表單填寫

程式碼遷移範例

範例1：從PDF中提取文字

之前（PdfiumViewer）：

// NuGet: Install-Package PdfiumViewer  (Apache 2.0； archived Aug 2019, .NET Framework 2.0+)
//        or Install-Package PdfiumViewer.Updated  (maintained fork, .NET Core / .NET 6)
//        or Install-Package PDFiumCore             (Dtronix, .NET Standard 2.1 P/Invoke)
//        or Install-Package Pdfium.Net.SDK         (Patagames, commercial perpetual license)
using PdfiumViewer;
using System;
using System.IO;
using System.Text;

class Program
{
    static void Main()
    {
        string pdfPath = "document.pdf";

        using (var document = PdfDocument.Load(pdfPath))
        {
            StringBuilder text = new StringBuilder();

            for (int i = 0; i < document.PageCount; i++)
            {
                // PdfiumViewer's text extraction is per-page raw text via GetPdfText(int).
                // No layout / format metadata is exposed.
                string pageText = document.GetPdfText(i);
                text.AppendLine(pageText);
            }

            Console.WriteLine(text.ToString());
        }
    }
}

// NuGet: Install-Package PdfiumViewer  (Apache 2.0； archived Aug 2019, .NET Framework 2.0+)
//        or Install-Package PdfiumViewer.Updated  (maintained fork, .NET Core / .NET 6)
//        or Install-Package PDFiumCore             (Dtronix, .NET Standard 2.1 P/Invoke)
//        or Install-Package Pdfium.Net.SDK         (Patagames, commercial perpetual license)
using PdfiumViewer;
using System;
using System.IO;
using System.Text;

class Program
{
    static void Main()
    {
        string pdfPath = "document.pdf";

        using (var document = PdfDocument.Load(pdfPath))
        {
            StringBuilder text = new StringBuilder();

            for (int i = 0; i < document.PageCount; i++)
            {
                // PdfiumViewer's text extraction is per-page raw text via GetPdfText(int).
                // No layout / format metadata is exposed.
                string pageText = document.GetPdfText(i);
                text.AppendLine(pageText);
            }

            Console.WriteLine(text.ToString());
        }
    }
}

之後（IronPDF）：

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

class Program
{
    static void Main()
    {
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

        string pdfPath = "document.pdf";

        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        Console.WriteLine(text);
    }
}

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

class Program
{
    static void Main()
    {
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

        string pdfPath = "document.pdf";

        var pdf = PdfDocument.FromFile(pdfPath);
        string text = pdf.ExtractAllText();

        Console.WriteLine(text);
    }
}

Imports IronPdf
Imports System

Class Program
    Shared Sub Main()
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

        Dim pdfPath As String = "document.pdf"

        Dim pdf = PdfDocument.FromFile(pdfPath)
        Dim text As String = pdf.ExtractAllText()

        Console.WriteLine(text)
    End Sub
End Class

Imports IronPdf
Imports System

Class Program
    Shared Sub Main()
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

        Dim pdfPath As String = "document.pdf"

        Dim pdf = PdfDocument.FromFile(pdfPath)
        Dim text As String = pdf.ExtractAllText()

        Console.WriteLine(text)
    End Sub
End Class

這裏的差異顯著。 PdfiumViewer需要手動迴圈遍歷每個頁面，使用using語句以正確處理—返回的文字是每頁的原始文字，沒有布局/格式元資料。

IronPDF簡化為幾行程式碼：使用PdfDocument.FromFile() 載入，使用ExtractAllText()提取並輸出。 The ExtractAllText() 方法自動處理所有頁面。如果需要每頁提取，您可以使用pdf.Pages[index].Text。查看文字提取文件以獲取更多選擇。

範例2：PDF合併

之前（PdfiumViewer）：

// NuGet: Install-Package PdfiumViewer  (representative open-source PDFium wrapper)
// PdfiumViewer and PDFiumCore do not expose PDF merge APIs - PDFium itself
// is a rendering / parsing engine, not a document-authoring engine.
// (Patagames Pdfium.Net.SDK exposes some document-edit operations but is commercial.)
using PdfiumViewer;
using System;
using System.IO;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<string> pdfFiles = new List<string>
        {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        };

        // To merge PDFs from a PDFium wrapper you must reach for another library
        // (PdfSharp, iText, IronPDF) or, with Patagames Pdfium.Net.SDK, use its
        // document-edit APIs.

        Console.WriteLine("PDF merging is not supported by PdfiumViewer / PDFiumCore.");
    }
}

// NuGet: Install-Package PdfiumViewer  (representative open-source PDFium wrapper)
// PdfiumViewer and PDFiumCore do not expose PDF merge APIs - PDFium itself
// is a rendering / parsing engine, not a document-authoring engine.
// (Patagames Pdfium.Net.SDK exposes some document-edit operations but is commercial.)
using PdfiumViewer;
using System;
using System.IO;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<string> pdfFiles = new List<string>
        {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        };

        // To merge PDFs from a PDFium wrapper you must reach for another library
        // (PdfSharp, iText, IronPDF) or, with Patagames Pdfium.Net.SDK, use its
        // document-edit APIs.

        Console.WriteLine("PDF merging is not supported by PdfiumViewer / PDFiumCore.");
    }
}

Imports PdfiumViewer
Imports System
Imports System.IO
Imports System.Collections.Generic

Module Program
    Sub Main()
        Dim pdfFiles As New List(Of String) From {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        }

        ' To merge PDFs from a PDFium wrapper you must reach for another library
        ' (PdfSharp, iText, IronPDF) or, with Patagames Pdfium.Net.SDK, use its
        ' document-edit APIs.

        Console.WriteLine("PDF merging is not supported by PdfiumViewer / PDFiumCore.")
    End Sub
End Module

Imports PdfiumViewer
Imports System
Imports System.IO
Imports System.Collections.Generic

Module Program
    Sub Main()
        Dim pdfFiles As New List(Of String) From {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        }

        ' To merge PDFs from a PDFium wrapper you must reach for another library
        ' (PdfSharp, iText, IronPDF) or, with Patagames Pdfium.Net.SDK, use its
        ' document-edit APIs.

        Console.WriteLine("PDF merging is not supported by PdfiumViewer / PDFiumCore.")
    End Sub
End Module

之後（IronPDF）：

// NuGet: Install-Package IronPdf
using IronPdf;
using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

        List<string> pdfFiles = new List<string>
        {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        };

        // PdfDocument.Merge accepts an IEnumerable<PdfDocument>, so load each file first.
        var docs = pdfFiles.Select(path => PdfDocument.FromFile(path)).ToList();
        var merged = PdfDocument.Merge(docs);
        merged.SaveAs("merged.pdf");

        Console.WriteLine("PDFs merged successfully");
    }
}

// NuGet: Install-Package IronPdf
using IronPdf;
using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

        List<string> pdfFiles = new List<string>
        {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        };

        // PdfDocument.Merge accepts an IEnumerable<PdfDocument>, so load each file first.
        var docs = pdfFiles.Select(path => PdfDocument.FromFile(path)).ToList();
        var merged = PdfDocument.Merge(docs);
        merged.SaveAs("merged.pdf");

        Console.WriteLine("PDFs merged successfully");
    }
}

Imports IronPdf
Imports System
Imports System.Collections.Generic
Imports System.Linq

Module Program
    Sub Main()
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

        Dim pdfFiles As New List(Of String) From {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        }

        ' PdfDocument.Merge accepts an IEnumerable(Of PdfDocument), so load each file first.
        Dim docs = pdfFiles.Select(Function(path) PdfDocument.FromFile(path)).ToList()
        Dim merged = PdfDocument.Merge(docs)
        merged.SaveAs("merged.pdf")

        Console.WriteLine("PDFs merged successfully")
    End Sub
End Module

Imports IronPdf
Imports System
Imports System.Collections.Generic
Imports System.Linq

Module Program
    Sub Main()
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

        Dim pdfFiles As New List(Of String) From {
            "document1.pdf",
            "document2.pdf",
            "document3.pdf"
        }

        ' PdfDocument.Merge accepts an IEnumerable(Of PdfDocument), so load each file first.
        Dim docs = pdfFiles.Select(Function(path) PdfDocument.FromFile(path)).ToList()
        Dim merged = PdfDocument.Merge(docs)
        merged.SaveAs("merged.pdf")

        Console.WriteLine("PDFs merged successfully")
    End Sub
End Module

此範例顯示了功能差距。免費PDFium包（PdfiumViewer、PDFiumCore）不提供合併API；Patagames Pdfium.Net.SDK提供一些文件編輯操作，但它是商業的。

IronPDF提供了本地合併，使用靜態PdfDocument.FromFile()載入每個輸入文件，然後合併生成的文件。結果是一個新的SaveAs()保存。了解更多合併和拆分PDF的資訊。

範例3：HTML到PDF轉換

之前（PdfiumViewer）：

// NuGet: Install-Package PdfiumViewer  (representative PDFium wrapper)
// PDFium is a PDF rendering / parsing engine. It has NO HTML parser, so no
// PDFium .NET wrapper (PdfiumViewer, PdfiumViewer.Updated, PDFiumCore,
// Pdfium.Net.SDK) can convert HTML to PDF on its own.
using PdfiumViewer;
using System;
using System.IO;
using System.Drawing.Printing;

class Program
{
    static void Main()
    {
        // PDFium has no native HTML-to-PDF capability.
        // Produce the PDF with another engine (wkhtmltopdf, headless Chromium,
        // IronPDF, etc.) and then load it with PdfDocument.Load(...) for rendering.
        string htmlContent = "<h1>Hello World</h1>";

        Console.WriteLine("HTML to PDF conversion is not supported by PDFium.");
    }
}

// NuGet: Install-Package PdfiumViewer  (representative PDFium wrapper)
// PDFium is a PDF rendering / parsing engine. It has NO HTML parser, so no
// PDFium .NET wrapper (PdfiumViewer, PdfiumViewer.Updated, PDFiumCore,
// Pdfium.Net.SDK) can convert HTML to PDF on its own.
using PdfiumViewer;
using System;
using System.IO;
using System.Drawing.Printing;

class Program
{
    static void Main()
    {
        // PDFium has no native HTML-to-PDF capability.
        // Produce the PDF with another engine (wkhtmltopdf, headless Chromium,
        // IronPDF, etc.) and then load it with PdfDocument.Load(...) for rendering.
        string htmlContent = "<h1>Hello World</h1>";

        Console.WriteLine("HTML to PDF conversion is not supported by PDFium.");
    }
}

Imports PdfiumViewer
Imports System
Imports System.IO
Imports System.Drawing.Printing

Module Program
    Sub Main()
        ' PDFium has no native HTML-to-PDF capability.
        ' Produce the PDF with another engine (wkhtmltopdf, headless Chromium,
        ' IronPDF, etc.) and then load it with PdfDocument.Load(...) for rendering.
        Dim htmlContent As String = "<h1>Hello World</h1>"

        Console.WriteLine("HTML to PDF conversion is not supported by PDFium.")
    End Sub
End Module

Imports PdfiumViewer
Imports System
Imports System.IO
Imports System.Drawing.Printing

Module Program
    Sub Main()
        ' PDFium has no native HTML-to-PDF capability.
        ' Produce the PDF with another engine (wkhtmltopdf, headless Chromium,
        ' IronPDF, etc.) and then load it with PdfDocument.Load(...) for rendering.
        Dim htmlContent As String = "<h1>Hello World</h1>"

        Console.WriteLine("HTML to PDF conversion is not supported by PDFium.")
    End Sub
End Module

之後（IronPDF）：

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

class Program
{
    static void Main()
    {
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

        var renderer = new ChromePdfRenderer();
        string htmlContent = "<h1>Hello World</h1>";

        var pdf = renderer.RenderHtmlAsPdf(htmlContent);
        pdf.SaveAs("output.pdf");

        Console.WriteLine("PDF created successfully");
    }
}

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

class Program
{
    static void Main()
    {
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

        var renderer = new ChromePdfRenderer();
        string htmlContent = "<h1>Hello World</h1>";

        var pdf = renderer.RenderHtmlAsPdf(htmlContent);
        pdf.SaveAs("output.pdf");

        Console.WriteLine("PDF created successfully");
    }
}

Imports IronPdf
Imports System

Module Program
    Sub Main()
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

        Dim renderer As New ChromePdfRenderer()
        Dim htmlContent As String = "<h1>Hello World</h1>"

        Dim pdf = renderer.RenderHtmlAsPdf(htmlContent)
        pdf.SaveAs("output.pdf")

        Console.WriteLine("PDF created successfully")
    End Sub
End Module

Imports IronPdf
Imports System

Module Program
    Sub Main()
        IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

        Dim renderer As New ChromePdfRenderer()
        Dim htmlContent As String = "<h1>Hello World</h1>"

        Dim pdf = renderer.RenderHtmlAsPdf(htmlContent)
        pdf.SaveAs("output.pdf")

        Console.WriteLine("PDF created successfully")
    End Sub
End Module

此範例演示了最顯著的功能差異。 PDFium沒有HTML解析器，因此沒有圍繞它的.NET包可以自行將HTML轉換為PDF。

IronPDF以ChromePdfRenderer提供本地HTML到PDF轉換，該方法內部使用Chromium引擎，以便準確渲染HTML、CSS和JavaScript。 RenderHtmlAsPdf()方法將HTML字串直接轉換為PDF文件。 IronPDF也可以用RenderHtmlFileAsPdf()渲染HTML文件。查看更多HTML到PDF文件以獲得完整的範例。

取消本機依賴

從PDFium包遷移到IronPDF的最大優勢之一是取消本機二進制管理。

之前（PDFium包）- 複雜的部署

MyApp/
├── bin/
│   ├── MyApp.dll
│   ├── PdfiumViewer.dll      # or PDFiumCore.dll / Patagames.Pdf.dll
│   ├── x86/
│   │   └── pdfium.dll
│   └── x64/
│       └── pdfium.dll
├── runtimes/
│   ├── win-x86/native/
│   │   └── pdfium.dll
│   ├── win-x64/native/
│   │   └── pdfium.dll
│   ├── linux-x64/native/
│   │   └── libpdfium.so
│   └── osx-x64/native/
│       └── libpdfium.dylib

MyApp/
├── bin/
│   ├── MyApp.dll
│   ├── PdfiumViewer.dll      # or PDFiumCore.dll / Patagames.Pdf.dll
│   ├── x86/
│   │   └── pdfium.dll
│   └── x64/
│       └── pdfium.dll
├── runtimes/
│   ├── win-x86/native/
│   │   └── pdfium.dll
│   ├── win-x64/native/
│   │   └── pdfium.dll
│   ├── linux-x64/native/
│   │   └── libpdfium.so
│   └── osx-x64/native/
│       └── libpdfium.dylib

Text

之後（IronPDF）- 清晰的部署

MyApp/
├── bin/
│   ├── MyApp.dll
│   └── IronPdf.dll  # 包含所有內容

MyApp/
├── bin/
│   ├── MyApp.dll
│   └── IronPdf.dll  # 包含所有內容

Text

取消本機二進制引用

# Delete native PDFium binaries
rm -rf x86/x64/runtimes/

# Remove from .csproj
# Delete any <Content Include="pdfium.dll" /> entries
# Delete any <None Include="x86/pdfium.dll" /> entries

# Delete native PDFium binaries
rm -rf x86/x64/runtimes/

# Remove from .csproj
# Delete any <Content Include="pdfium.dll" /> entries
# Delete any <None Include="x86/pdfium.dll" /> entries

SHELL

關鍵遷移注意事項

比例到DPI的轉換

PdfiumViewer的Render(...)需要顯式dpiX/dpiY，而PDFium的底層渲染是按比例驅動的（1.0 = 72 DPI）。 IronPDF直接使用DPI：

// Formula:IronPDFDPI = 72 × PDFium scale
// PDFium scale 2.0 →IronPDFDPI 144
pdf.RasterizeToImageFiles("*.png", DPI: 144);

// Formula:IronPDFDPI = 72 × PDFium scale
// PDFium scale 2.0 →IronPDFDPI 144
pdf.RasterizeToImageFiles("*.png", DPI: 144);

文件載入方法更改

// PdfiumViewer
PdfDocument.Load(path)

// IronPDF
PdfDocument.FromFile(path)

// PdfiumViewer
PdfDocument.Load(path)

// IronPDF
PdfDocument.FromFile(path)

' PdfiumViewer
PdfDocument.Load(path)

' IronPDF
PdfDocument.FromFile(path)

' PdfiumViewer
PdfDocument.Load(path)

' IronPDF
PdfDocument.FromFile(path)

保存方法更改

// PdfiumViewer (takes a Stream)
document.Save(stream)

//IronPDF(takes a path)
pdf.SaveAs(path)

// PdfiumViewer (takes a Stream)
document.Save(stream)

//IronPDF(takes a path)
pdf.SaveAs(path)

簡化的處理模式

// PdfiumViewer: explicit disposal of document and the rendered Image
using (var document = PdfDocument.Load(path))
using (var bitmap = document.Render(0, 1024, 768, 96, 96, PdfRenderFlags.None))
{
    bitmap.Save("output.png");
}

// IronPDF: Simplified
var pdf = PdfDocument.FromFile(path);
pdf.RasterizeToImageFiles("output.png");

// PdfiumViewer: explicit disposal of document and the rendered Image
using (var document = PdfDocument.Load(path))
using (var bitmap = document.Render(0, 1024, 768, 96, 96, PdfRenderFlags.None))
{
    bitmap.Save("output.png");
}

// IronPDF: Simplified
var pdf = PdfDocument.FromFile(path);
pdf.RasterizeToImageFiles("output.png");

Imports PdfiumViewer

' PdfiumViewer: explicit disposal of document and the rendered Image
Using document = PdfDocument.Load(path)
    Using bitmap = document.Render(0, 1024, 768, 96, 96, PdfRenderFlags.None)
        bitmap.Save("output.png")
    End Using
End Using

' IronPDF: Simplified
Dim pdf = PdfDocument.FromFile(path)
pdf.RasterizeToImageFiles("output.png")

Imports PdfiumViewer

' PdfiumViewer: explicit disposal of document and the rendered Image
Using document = PdfDocument.Load(path)
    Using bitmap = document.Render(0, 1024, 768, 96, 96, PdfRenderFlags.None)
        bitmap.Save("output.png")
    End Using
End Using

' IronPDF: Simplified
Dim pdf = PdfDocument.FromFile(path)
pdf.RasterizeToImageFiles("output.png")

移除平臺特定程式碼

// PDFium wrapper: required platform detection / RID-specific binaries
#if WIN64
    // Load x64 pdfium.dll
#else
    // Load x86 pdfium.dll
#endif

// IronPDF: Remove all platform-specific code
// Just use the API directly

// PDFium wrapper: required platform detection / RID-specific binaries
#if WIN64
    // Load x64 pdfium.dll
#else
    // Load x86 pdfium.dll
#endif

// IronPDF: Remove all platform-specific code
// Just use the API directly

net

net

功能比較總結

功能	PDFium .NET包	IronPDF
載入PDF	是	是
渲染到圖像	是	是
提取文字	是（基本的，每頁）	是（邏輯/視覺順序）
頁面資訊	是	是
從HTML建立	None	是
從URL建立	None	是
合併PDF	免費包：無；Patagames：部分	是
拆分PDF	免費包：無；Patagames：部分	是
新增水印	未內建	是
頁眉/頁腳	未內建	是
表單填寫	免費包：無；Patagames：是	是
數位簽名	免費包：無；Patagames：是	是
密碼保護	免費包：無；Patagames：是	是
本機依賴	必需的	捆綁/ NuGet管理
跨平臺	複雜的（每RID本機二進制）	自動
記憶體管理	手動處理	簡化

遷移檢查表

遷移前

確認使用的PDFium包是什麼（PdfiumViewer / PdfiumViewer.Updated / PDFiumCore / Pdfium.Net.SDK）
記錄當前渲染尺寸/DPI/使用的比例
列出項目中的本機二進制位置（每RID）
檢查平臺特定的載入程式碼
確認PDF建立需求（目前是否使用單獨的工具？）
審查轉換的處理模式
獲得IronPDF授權金鑰

套件變更

刪除PDFium包NuGet包：Pdfium.Net.SDK
從pdfium.dll / .so / .dylib二進制文件
移除平臺特定的條件編譯
更新.csproj以移除本機二進制引用
安裝IronPdf NuGet包：dotnet add package IronPdf

程式碼變更

在啟動時加入授權金鑰配置
將PdfDocument.FromFile()
將pdf.SaveAs()
將pdf.ExtractAllText()
將比例因數轉換為DPI值（DPI = 72 × 比例）
簡化的處理模式（移除巢狀的using語句）
移除平臺特定程式碼

遷移後

測試渲染輸出質量
比較文字提取結果
測試跨平台部署
新增新功能（HTML到PDF，合併，水印，安全性）
更新文件

請注意: PDFium是Google LLC的一個專案，根據BSD-3-Clause發布。 PdfiumViewer、PDFiumCore和Pdfium.Net.SDK是其各自所有者（pvginkel、Dtronix和Patagames Software Ltd）的商標。本網站與Google、Chromium專案或任何包作者無關、未受到擁護或贊助。所有產品名稱、標誌和品牌均為其各自所有者的財產。比較僅供參考，反映撰寫時公開可用的資訊。