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

如何用 C# 用響應式 CSS 將 HTML 轉換為 PDF

Curtis Chau

Updated: 2026年5月18日

雖然ComPDFKit提供穩固的PDF操作功能，但有許多因素使開發團隊考慮更成熟的替代方案。

市場成熟度與生態系統比較

ComPDFKit面臨於新進市場參與者通常會遇到的挑戰：文件空缺、較小的社群，及有限的Stack Overflow涵蓋範圍。 IronPDF經過十年的改進，提供企業專案所需的穩定性和資源。

方面	ComPDFKit	IronPDF
HTML到PDF	需要手動HTML解析	原生Chromium渲染
市場成熟度	較新的參與者	10年以上，經過考驗
社群規模	較小，有限的Stack Overflow	大型、活躍的社群
文件	一些空缺	廣泛的教程與指南
下載次數	正在增長	超過1,000萬次NuGet下載
API風格	受到C++影響，冗長	現代的 .NET 流利API
記憶體管理	手動`Release()`呼叫	自動GC處理

功能對等

兩個程式庫都支援全面的PDF功能：

功能	ComPDFKit	IronPDF
HTML轉PDF	基礎/手動	✅ 原生Chromium
URL到PDF	手動實現	✅ 內建
從頭建立PDF	✅	✅
PDF編輯	✅	✅
文字提取	✅	✅
合併/分割	✅	✅
數位簽名	✅	✅
表單填寫	✅	✅
浮水印	✅	✅
跨平台	Windows、Linux、macOS	Windows、Linux、macOS

主要遷移利益

**更優秀的HTML渲染：**IronPDF的Chromium引擎能夠原生處理現代CSS3、JavaScript和響應式佈局
**成熟的生態系統：**超過10年的改進，廣泛的文件資料，並經過考驗的穩定性
**更簡單的API：**更少樣板程式碼，無需手動記憶體管理與Release()呼叫
**更好的 .NET整合：**原生async/await、LINQ支持、流利的介面
**豐富的資源：**成千上萬的Stack Overflow答案和社群範例

遷移前準備

前提條件

確保您的環境符合以下要求：

.NET Framework 4.6.2+ or .NET Core 3.1 / .NET 5-9
Visual Studio 2019+或VS Code與C#擴展
NuGet包管理器存取 -IronPDF許可證金鑰（免費試用可在 ironpdf.com 獲得）

審核ComPDFKit使用情形

在您的解決方案目錄中執行這些指令，以識別所有ComPDFKit的參考資料：

# Find allComPDFKitusages in your codebase
grep -r "using ComPDFKit" --include="*.cs" .
grep -r "CPDFDocument\|CPDFPage\|CPDFAnnotation" --include="*.cs" .

# Find NuGet package references
grep -r "ComPDFKit" --include="*.csproj" .

# Find allComPDFKitusages in your codebase
grep -r "using ComPDFKit" --include="*.cs" .
grep -r "CPDFDocument\|CPDFPage\|CPDFAnnotation" --include="*.cs" .

# Find NuGet package references
grep -r "ComPDFKit" --include="*.csproj" .

SHELL

預期的中斷變更

更改	ComPDFKit	IronPDF	影響
文件載入	`CPDFDocument.InitWithFilePath()`	`PdfDocument.FromFile()`	方法名稱變更
保存	`document.WriteToFilePath()`	`pdf.SaveAs()`	方法名稱變更
記憶體清理	需要`document.Release()`	自動(GC)	移除手動清理
頁面存取	`document.PageAtIndex(i)`	`pdf.Pages[i]`	陣列樣式存取
頁面索引	0起始基數	0起始基數	不需要變更
HTML 渲染	手動實現	`RenderHtmlAsPdf()`	主要簡化
文字提取	`textPage.GetText()`	`pdf.ExtractAllText()`	簡化的API

逐步遷移過程

步驟1：更新NuGet包

移除ComPDFKit套件並安裝IronPDF：

# RemoveComPDFKitpackages
dotnet remove package ComPDFKit.NetCore
dotnet remove package ComPDFKit.NetFramework

# Install IronPDF
dotnet add package IronPdf

# RemoveComPDFKitpackages
dotnet remove package ComPDFKit.NetCore
dotnet remove package ComPDFKit.NetFramework

# Install IronPDF
dotnet add package IronPdf

SHELL

步驟 2：更新命名空間引用

將ComPDFKit命名空間替換為IronPDF：

// Remove these
using ComPDFKit.PDFDocument;
using ComPDFKit.PDFPage;
using ComPDFKit.PDFAnnotation;
using ComPDFKit.Import;

// Add this
using IronPdf;

// Remove these
using ComPDFKit.PDFDocument;
using ComPDFKit.PDFPage;
using ComPDFKit.PDFAnnotation;
using ComPDFKit.Import;

// Add this
using IronPdf;

Imports IronPdf

Imports IronPdf

步驟3：配置授權

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

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

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

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

完整 API 遷移參考

文件操作

任務	ComPDFKit	IronPDF
建立空文件	`CPDFDocument.CreateDocument()`	`new PdfDocument()`
從檔案載入	`CPDFDocument.InitWithFilePath(path)`	`PdfDocument.FromFile(path)`
從流載入	`CPDFDocument.InitWithStream(stream)`	`PdfDocument.FromStream(stream)`
保存到檔案	`document.WriteToFilePath(path)`	`pdf.SaveAs(path)`
獲取頁數	`document.PageCount`	`pdf.PageCount`
釋放/處置	`document.Release()`	不需要

HTML到PDF轉換

任務	ComPDFKit	IronPDF
HTML字串轉PDF	需要手動實現	`renderer.RenderHtmlAsPdf(html)`
HTML文件轉PDF	需要手動實現	`renderer.RenderHtmlFileAsPdf(path)`
URL到PDF	需要手動實現	`renderer.RenderUrlAsPdf(url)`
設定頁面大小	透過頁面建立參數	`renderer.RenderingOptions.PaperSize`
設定邊距	透過編輯器配置	`renderer.RenderingOptions.MarginTop`等

合併和分割操作

任務	ComPDFKit	IronPDF
合併文件	`doc1.ImportPagesAtIndex(doc2, range, index)`	`PdfDocument.Merge(pdf1, pdf2)`
分割文件	提取頁面到新文件	`pdf.CopyPages(start, end)`

程式碼遷移範例

HTML到PDF轉換

ComPDFKit與IronPDF之間最大的不同在於HTML渲染。 ComPDFKit需要手動文字放置，而IronPDF利用其Chromium引擎原生進行HTML渲染。

ComPDFKit實現：

// NuGet: Install-Package ComPDFKit.NetCore
using ComPDFKit.PDFDocument;
using System;

class Program
{
    static void Main()
    {
        // ComPDFKit's .NET SDK has no native HTML-to-PDF rendering.
        // The closest equivalent is to create a blank document and lay
        // out primitives manually, or call ComPDFKit's separate cloud
        // Conversion API (a different SKU).
        var document = CPDFDocument.CreateDocument();
        document.InsertPage(0, 595, 842, string.Empty);

        document.WriteToFilePath("output.pdf");
        document.Release();
    }
}

// NuGet: Install-Package ComPDFKit.NetCore
using ComPDFKit.PDFDocument;
using System;

class Program
{
    static void Main()
    {
        // ComPDFKit's .NET SDK has no native HTML-to-PDF rendering.
        // The closest equivalent is to create a blank document and lay
        // out primitives manually, or call ComPDFKit's separate cloud
        // Conversion API (a different SKU).
        var document = CPDFDocument.CreateDocument();
        document.InsertPage(0, 595, 842, string.Empty);

        document.WriteToFilePath("output.pdf");
        document.Release();
    }
}

Imports ComPDFKit.PDFDocument
Imports System

Module Program
    Sub Main()
        ' ComPDFKit's .NET SDK has no native HTML-to-PDF rendering.
        ' The closest equivalent is to create a blank document and lay
        ' out primitives manually, or call ComPDFKit's separate cloud
        ' Conversion API (a different SKU).
        Dim document = CPDFDocument.CreateDocument()
        document.InsertPage(0, 595, 842, String.Empty)

        document.WriteToFilePath("output.pdf")
        document.Release()
    End Sub
End Module

Imports ComPDFKit.PDFDocument
Imports System

Module Program
    Sub Main()
        ' ComPDFKit's .NET SDK has no native HTML-to-PDF rendering.
        ' The closest equivalent is to create a blank document and lay
        ' out primitives manually, or call ComPDFKit's separate cloud
        ' Conversion API (a different SKU).
        Dim document = CPDFDocument.CreateDocument()
        document.InsertPage(0, 595, 842, String.Empty)

        document.WriteToFilePath("output.pdf")
        document.Release()
    End Sub
End Module

IronPDF實現：

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1><p>This is HTML content.</p>");
        pdf.SaveAs("output.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1><p>This is HTML content.</p>");
        pdf.SaveAs("output.pdf");
    }
}

Imports IronPdf
Imports System

Class Program
    Shared Sub Main()
        Dim renderer = New ChromePdfRenderer()
        Dim pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1><p>This is HTML content.</p>")
        pdf.SaveAs("output.pdf")
    End Sub
End Class

Imports IronPdf
Imports System

Class Program
    Shared Sub Main()
        Dim renderer = New ChromePdfRenderer()
        Dim pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1><p>This is HTML content.</p>")
        pdf.SaveAs("output.pdf")
    End Sub
End Class

IronPDF的ChromePdfRenderer消除了手動文字定位和編輯器管理的需求。欲了解更多HTML轉換選項，請參閱 HTML到PDF文件。

合併多個 PDF

ComPDFKit實現：

// NuGet: Install-Package ComPDFKit.NetCore
using ComPDFKit.PDFDocument;
using ComPDFKit.Import;
using System;

class Program
{
    static void Main()
    {
        var document1 = CPDFDocument.InitWithFilePath("file1.pdf");
        var document2 = CPDFDocument.InitWithFilePath("file2.pdf");
        
        // Import pages from document2 into document1
        document1.ImportPagesAtIndex(document2, "0-" + (document2.PageCount - 1), document1.PageCount);
        
        document1.WriteToFilePath("merged.pdf");
        document1.Release();
        document2.Release();
    }
}

// NuGet: Install-Package ComPDFKit.NetCore
using ComPDFKit.PDFDocument;
using ComPDFKit.Import;
using System;

class Program
{
    static void Main()
    {
        var document1 = CPDFDocument.InitWithFilePath("file1.pdf");
        var document2 = CPDFDocument.InitWithFilePath("file2.pdf");
        
        // Import pages from document2 into document1
        document1.ImportPagesAtIndex(document2, "0-" + (document2.PageCount - 1), document1.PageCount);
        
        document1.WriteToFilePath("merged.pdf");
        document1.Release();
        document2.Release();
    }
}

' NuGet: Install-Package ComPDFKit.NetCore
Imports ComPDFKit.PDFDocument
Imports ComPDFKit.Import
Imports System

Module Program
    Sub Main()
        Dim document1 = CPDFDocument.InitWithFilePath("file1.pdf")
        Dim document2 = CPDFDocument.InitWithFilePath("file2.pdf")
        
        ' Import pages from document2 into document1
        document1.ImportPagesAtIndex(document2, "0-" & (document2.PageCount - 1).ToString(), document1.PageCount)
        
        document1.WriteToFilePath("merged.pdf")
        document1.Release()
        document2.Release()
    End Sub
End Module

' NuGet: Install-Package ComPDFKit.NetCore
Imports ComPDFKit.PDFDocument
Imports ComPDFKit.Import
Imports System

Module Program
    Sub Main()
        Dim document1 = CPDFDocument.InitWithFilePath("file1.pdf")
        Dim document2 = CPDFDocument.InitWithFilePath("file2.pdf")
        
        ' Import pages from document2 into document1
        document1.ImportPagesAtIndex(document2, "0-" & (document2.PageCount - 1).ToString(), document1.PageCount)
        
        document1.WriteToFilePath("merged.pdf")
        document1.Release()
        document2.Release()
    End Sub
End Module

IronPDF實現：

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

class Program
{
    static void Main()
    {
        var pdf1 = PdfDocument.FromFile("file1.pdf");
        var pdf2 = PdfDocument.FromFile("file2.pdf");
        
        var merged = PdfDocument.Merge(new List<PdfDocument> { pdf1, pdf2 });
        merged.SaveAs("merged.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        var pdf1 = PdfDocument.FromFile("file1.pdf");
        var pdf2 = PdfDocument.FromFile("file2.pdf");
        
        var merged = PdfDocument.Merge(new List<PdfDocument> { pdf1, pdf2 });
        merged.SaveAs("merged.pdf");
    }
}

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports System
Imports System.Collections.Generic

Module Program
    Sub Main()
        Dim pdf1 = PdfDocument.FromFile("file1.pdf")
        Dim pdf2 = PdfDocument.FromFile("file2.pdf")

        Dim merged = PdfDocument.Merge(New List(Of PdfDocument) From {pdf1, pdf2})
        merged.SaveAs("merged.pdf")
    End Sub
End Module

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports System
Imports System.Collections.Generic

Module Program
    Sub Main()
        Dim pdf1 = PdfDocument.FromFile("file1.pdf")
        Dim pdf2 = PdfDocument.FromFile("file2.pdf")

        Dim merged = PdfDocument.Merge(New List(Of PdfDocument) From {pdf1, pdf2})
        merged.SaveAs("merged.pdf")
    End Sub
End Module

IronPDF的靜態ImportPagesAtIndex模式冗長。欲了解更多選項，請參閱 PDF合併文件。

新增水印

浮水印顯示出ComPDFKit的屬性驅動CPDFWatermark配置與IronPDF的基於HTML的樣式的不同。

ComPDFKit實現：

// NuGet: Install-Package ComPDFKit.NetCore
using ComPDFKit.PDFDocument;
using ComPDFKit.PDFWatermark;
using System;

class Program
{
    static void Main()
    {
        var document = CPDFDocument.InitWithFilePath("input.pdf");

        CPDFWatermark watermark = document.InitWatermark(
            C_Watermark_Type.WATERMARK_TYPE_TEXT);
        watermark.SetText("CONFIDENTIAL");
        watermark.SetFontName("Helvetica");
        watermark.SetFontSize(48);
        watermark.SetTextRGBColor(255, 0, 0);
        watermark.SetRotation(45);
        watermark.SetOpacity(76); // 0..255
        watermark.SetVertalign(C_Watermark_Vertalign.WATERMARK_VERTALIGN_CENTER);
        watermark.SetHorizalign(C_Watermark_Horizalign.WATERMARK_HORIZALIGN_CENTER);
        watermark.SetPages($"0-{document.PageCount - 1}");
        watermark.SetFront(true);
        watermark.CreateWatermark();

        document.WriteToFilePath("watermarked.pdf");
        document.Release();
    }
}

// NuGet: Install-Package ComPDFKit.NetCore
using ComPDFKit.PDFDocument;
using ComPDFKit.PDFWatermark;
using System;

class Program
{
    static void Main()
    {
        var document = CPDFDocument.InitWithFilePath("input.pdf");

        CPDFWatermark watermark = document.InitWatermark(
            C_Watermark_Type.WATERMARK_TYPE_TEXT);
        watermark.SetText("CONFIDENTIAL");
        watermark.SetFontName("Helvetica");
        watermark.SetFontSize(48);
        watermark.SetTextRGBColor(255, 0, 0);
        watermark.SetRotation(45);
        watermark.SetOpacity(76); // 0..255
        watermark.SetVertalign(C_Watermark_Vertalign.WATERMARK_VERTALIGN_CENTER);
        watermark.SetHorizalign(C_Watermark_Horizalign.WATERMARK_HORIZALIGN_CENTER);
        watermark.SetPages($"0-{document.PageCount - 1}");
        watermark.SetFront(true);
        watermark.CreateWatermark();

        document.WriteToFilePath("watermarked.pdf");
        document.Release();
    }
}

Imports ComPDFKit.PDFDocument
Imports ComPDFKit.PDFWatermark
Imports System

Class Program
    Shared Sub Main()
        Dim document = CPDFDocument.InitWithFilePath("input.pdf")

        Dim watermark As CPDFWatermark = document.InitWatermark(C_Watermark_Type.WATERMARK_TYPE_TEXT)
        watermark.SetText("CONFIDENTIAL")
        watermark.SetFontName("Helvetica")
        watermark.SetFontSize(48)
        watermark.SetTextRGBColor(255, 0, 0)
        watermark.SetRotation(45)
        watermark.SetOpacity(76) ' 0..255
        watermark.SetVertalign(C_Watermark_Vertalign.WATERMARK_VERTALIGN_CENTER)
        watermark.SetHorizalign(C_Watermark_Horizalign.WATERMARK_HORIZALIGN_CENTER)
        watermark.SetPages($"0-{document.PageCount - 1}")
        watermark.SetFront(True)
        watermark.CreateWatermark()

        document.WriteToFilePath("watermarked.pdf")
        document.Release()
    End Sub
End Class

Imports ComPDFKit.PDFDocument
Imports ComPDFKit.PDFWatermark
Imports System

Class Program
    Shared Sub Main()
        Dim document = CPDFDocument.InitWithFilePath("input.pdf")

        Dim watermark As CPDFWatermark = document.InitWatermark(C_Watermark_Type.WATERMARK_TYPE_TEXT)
        watermark.SetText("CONFIDENTIAL")
        watermark.SetFontName("Helvetica")
        watermark.SetFontSize(48)
        watermark.SetTextRGBColor(255, 0, 0)
        watermark.SetRotation(45)
        watermark.SetOpacity(76) ' 0..255
        watermark.SetVertalign(C_Watermark_Vertalign.WATERMARK_VERTALIGN_CENTER)
        watermark.SetHorizalign(C_Watermark_Horizalign.WATERMARK_HORIZALIGN_CENTER)
        watermark.SetPages($"0-{document.PageCount - 1}")
        watermark.SetFront(True)
        watermark.CreateWatermark()

        document.WriteToFilePath("watermarked.pdf")
        document.Release()
    End Sub
End Class

IronPDF實現：

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

class Program
{
    static void Main()
    {
        var pdf = PdfDocument.FromFile("input.pdf");
        
        pdf.ApplyWatermark("<h1 style='color:rgba(255,0,0,0.3);'>CONFIDENTIAL</h1>",
            rotation: 45,
            verticalAlignment: VerticalAlignment.Middle,
            horizontalAlignment: HorizontalAlignment.Center);
        
        pdf.SaveAs("watermarked.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        var pdf = PdfDocument.FromFile("input.pdf");
        
        pdf.ApplyWatermark("<h1 style='color:rgba(255,0,0,0.3);'>CONFIDENTIAL</h1>",
            rotation: 45,
            verticalAlignment: VerticalAlignment.Middle,
            horizontalAlignment: HorizontalAlignment.Center);
        
        pdf.SaveAs("watermarked.pdf");
    }
}

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports IronPdf.Editing
Imports System

Module Program
    Sub Main()
        Dim pdf = PdfDocument.FromFile("input.pdf")
        
        pdf.ApplyWatermark("<h1 style='color:rgba(255,0,0,0.3);'>CONFIDENTIAL</h1>", 
                           rotation:=45, 
                           verticalAlignment:=VerticalAlignment.Middle, 
                           horizontalAlignment:=HorizontalAlignment.Center)
        
        pdf.SaveAs("watermarked.pdf")
    End Sub
End Module

' NuGet: Install-Package IronPdf
Imports IronPdf
Imports IronPdf.Editing
Imports System

Module Program
    Sub Main()
        Dim pdf = PdfDocument.FromFile("input.pdf")
        
        pdf.ApplyWatermark("<h1 style='color:rgba(255,0,0,0.3);'>CONFIDENTIAL</h1>", 
                           rotation:=45, 
                           verticalAlignment:=VerticalAlignment.Middle, 
                           horizontalAlignment:=HorizontalAlignment.Center)
        
        pdf.SaveAs("watermarked.pdf")
    End Sub
End Module

IronPDF將多步CPDFWatermark配置簡化為單一方法呼叫與HTML/CSS樣式。如需更多選項，請參見浮水印文件。

文字提取

ComPDFKit實現：

using ComPDFKit.PDFDocument;
using System.Text;

var document = CPDFDocument.InitWithFilePath("document.pdf");

// Extract text (verbose)
var allText = new StringBuilder();
for (int i = 0; i < document.PageCount; i++)
{
    var page = document.PageAtIndex(i);
    var textPage = page.GetTextPage();
    allText.AppendLine(textPage.GetText(0, textPage.CountChars()));
    textPage.Release();
    page.Release();
}

document.WriteToFilePath("output.pdf");
document.Release(); // Must remember to release!

using ComPDFKit.PDFDocument;
using System.Text;

var document = CPDFDocument.InitWithFilePath("document.pdf");

// Extract text (verbose)
var allText = new StringBuilder();
for (int i = 0; i < document.PageCount; i++)
{
    var page = document.PageAtIndex(i);
    var textPage = page.GetTextPage();
    allText.AppendLine(textPage.GetText(0, textPage.CountChars()));
    textPage.Release();
    page.Release();
}

document.WriteToFilePath("output.pdf");
document.Release(); // Must remember to release!

Imports ComPDFKit.PDFDocument
Imports System.Text

Dim document = CPDFDocument.InitWithFilePath("document.pdf")

' Extract text (verbose)
Dim allText As New StringBuilder()
For i As Integer = 0 To document.PageCount - 1
    Dim page = document.PageAtIndex(i)
    Dim textPage = page.GetTextPage()
    allText.AppendLine(textPage.GetText(0, textPage.CountChars()))
    textPage.Release()
    page.Release()
Next

document.WriteToFilePath("output.pdf")
document.Release() ' Must remember to release!

Imports ComPDFKit.PDFDocument
Imports System.Text

Dim document = CPDFDocument.InitWithFilePath("document.pdf")

' Extract text (verbose)
Dim allText As New StringBuilder()
For i As Integer = 0 To document.PageCount - 1
    Dim page = document.PageAtIndex(i)
    Dim textPage = page.GetTextPage()
    allText.AppendLine(textPage.GetText(0, textPage.CountChars()))
    textPage.Release()
    page.Release()
Next

document.WriteToFilePath("output.pdf")
document.Release() ' Must remember to release!

IronPDF實現：

using IronPdf;

var pdf = PdfDocument.FromFile("document.pdf");

// Extract text (one-liner)
string allText = pdf.ExtractAllText();

pdf.SaveAs("output.pdf");
// No Release() needed - GC handles cleanup

using IronPdf;

var pdf = PdfDocument.FromFile("document.pdf");

// Extract text (one-liner)
string allText = pdf.ExtractAllText();

pdf.SaveAs("output.pdf");
// No Release() needed - GC handles cleanup

Imports IronPdf

Dim pdf = PdfDocument.FromFile("document.pdf")

' Extract text (one-liner)
Dim allText As String = pdf.ExtractAllText()

pdf.SaveAs("output.pdf")
' No Release() needed - GC handles cleanup

Imports IronPdf

Dim pdf = PdfDocument.FromFile("document.pdf")

' Extract text (one-liner)
Dim allText As String = pdf.ExtractAllText()

pdf.SaveAs("output.pdf")
' No Release() needed - GC handles cleanup

IronPDF將多行文字提取與手動Release()呼叫減至單一方法。更多的提取選項，請參閱文字提取文件。

密碼保護

IronPDF實現：

using IronPdf;

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf("<h1>Confidential Document</h1>");

// Set security
pdf.SecuritySettings.UserPassword = "userPassword";
pdf.SecuritySettings.OwnerPassword = "ownerPassword";
pdf.SecuritySettings.AllowUserPrinting = PdfPrintSecurity.FullPrintRights;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;

pdf.SaveAs("protected.pdf");

using IronPdf;

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf("<h1>Confidential Document</h1>");

// Set security
pdf.SecuritySettings.UserPassword = "userPassword";
pdf.SecuritySettings.OwnerPassword = "ownerPassword";
pdf.SecuritySettings.AllowUserPrinting = PdfPrintSecurity.FullPrintRights;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;

pdf.SaveAs("protected.pdf");

Imports IronPdf

Dim renderer As New ChromePdfRenderer()
Dim pdf = renderer.RenderHtmlAsPdf("<h1>Confidential Document</h1>")

' Set security
pdf.SecuritySettings.UserPassword = "userPassword"
pdf.SecuritySettings.OwnerPassword = "ownerPassword"
pdf.SecuritySettings.AllowUserPrinting = PdfPrintSecurity.FullPrintRights
pdf.SecuritySettings.AllowUserCopyPasteContent = False

pdf.SaveAs("protected.pdf")

Imports IronPdf

Dim renderer As New ChromePdfRenderer()
Dim pdf = renderer.RenderHtmlAsPdf("<h1>Confidential Document</h1>")

' Set security
pdf.SecuritySettings.UserPassword = "userPassword"
pdf.SecuritySettings.OwnerPassword = "ownerPassword"
pdf.SecuritySettings.AllowUserPrinting = PdfPrintSecurity.FullPrintRights
pdf.SecuritySettings.AllowUserCopyPasteContent = False

pdf.SaveAs("protected.pdf")

欲了解全面的安全選項，請參閱加密文件。

關鍵遷移注意事項

移除所有Release()呼叫

最有影響的改變是去除手動記憶體管理。 ComPDFKit需要在文件、頁面、文字頁面上顯式進行Release()呼叫。 IronPDF透過.NET垃圾回收自動處理這些操作。

//ComPDFKit- manual cleanup required
document.Release();
page.Release();
textPage.Release();

//IronPDF- no equivalent needed
// GC handles cleanup automatically

//ComPDFKit- manual cleanup required
document.Release();
page.Release();
textPage.Release();

//IronPDF- no equivalent needed
// GC handles cleanup automatically

'ComPDFKit- manual cleanup required
document.Release()
page.Release()
textPage.Release()

'IronPDF- no equivalent needed
' GC handles cleanup automatically

'ComPDFKit- manual cleanup required
document.Release()
page.Release()
textPage.Release()

'IronPDF- no equivalent needed
' GC handles cleanup automatically