從 Foxit PDF SDK 遷移到 IronPDF：（.NET 指南）

Foxit PDF挑戰賽

Foxit PDF SDK 是一個功能強大的企業級函式庫，但它也存在相當大的複雜性，可能會減慢開發速度：

1.複雜的授權系統：多種產品、SKU 和授權類型（按開發者、按伺服器、OEM 等）使得為您的專案選擇合適的選項變得困難。

2.企業定價：定價是為大型組織量身定制的，對於較小的團隊或個人開發人員來說可能難以承受。

3.手動安裝： Foxit PDF SDK 需要手動 DLL 引用或私有 NuGet 來源－沒有簡單的公共 NuGet 套件可用。

4.冗長的 API：使用Library.Initialize()進行函式庫初始化、錯誤代碼檢查以及明確呼叫Library.Release()會為每個操作增加大量的樣板程式碼。

5.單獨的 HTML 轉換外掛： HTML 到 PDF 的轉換需要額外購買外掛程式－它不包含在基本 SDK 中。

6.複雜配置：設定需要詳細的物件配置（例如， HTML2PDFSettingData ），具有多個屬性。

7. C++ 傳承： API 模式反映了 C++ 的起源，在現代 C# 應用程式中感覺不太自然。

Foxit PDF 與 IronPDF 對比

成本效益分析

從 Foxit PDF 遷移到 IronPDF 可帶來切實的開發優勢：透過更簡單的 API 降低複雜性，透過直覺的方法加快開發速度，相容於現代 .NET，包括 async/await 和 LINQ 支持，採用 HTML 優先方法利用現有的 Web 技能，以及無需單獨購買附加元件即可獲得所有功能。 當您計劃於 2025 年和 2026 年採用 .NET 10 和 C# 14 時，IronPDF 為 PDF 生成提供了一個面向未來的基礎。

先決條件

1. .NET 環境： IronPDF 支援 .NET Framework 4.6.2+、.NET Core 3.1+ 和 .NET 5/6/7/8/9+。
2. NuGet 存取權限：確保您可以從 NuGet 安裝套件。 3.許可證密鑰：請從ironpdf.com取得用於生產環境的 IronPDF 許可證密鑰。

備份您的項目

# Create a backup branch
git checkout -b pre-ironpdf-migration
git add .
git commit -m "Backup before Foxit PDF SDK to IronPDF migration"

# Create a backup branch
git checkout -b pre-ironpdf-migration
git add .
git commit -m "Backup before Foxit PDF SDK to IronPDF migration"

識別所有 Foxit PDF 使用情況

# Find all Foxit PDF SDK references
grep -r "foxit\|PDFDoc\|PDFPage\|Library.Initialize\|Library.Release" --include="*.cs" --include="*.csproj" .

# Find Foxit DLL references
find . -name "*.csproj" | xargs grep -l "Foxit\|fsdk"

# Find all Foxit PDF SDK references
grep -r "foxit\|PDFDoc\|PDFPage\|Library.Initialize\|Library.Release" --include="*.cs" --include="*.csproj" .

# Find Foxit DLL references
find . -name "*.csproj" | xargs grep -l "Foxit\|fsdk"

文件當前功能

遷移前，目錄：

• 您使用 Foxit PDF 的哪些功能（HTML 轉換、註解、表單、安全）？
• 許可證金鑰位置和初始化程式碼
• 自訂配置和設定
• 使用 ErrorCode 列舉的錯誤處理模式

步驟 1：更新 NuGet 套件

# Foxit PDF SDK typically requires manual removal of DLL references
# Check your .csproj for Foxit references and remove them

# Install IronPDF
dotnet add package IronPdf

# Foxit PDF SDK typically requires manual removal of DLL references
# Check your .csproj for Foxit references and remove them

# Install IronPDF
dotnet add package IronPdf

如果 .csproj 檔案中存在 Foxit PDF 引用，請手動刪除它們：

<!-- Remove these manually -->
<Reference Include="fsdk_dotnet">
    <HintPath>..\libs\Foxit\fsdk_dotnet.dll</HintPath>
</Reference>

<!-- Remove these manually -->
<Reference Include="fsdk_dotnet">
    <HintPath>..\libs\Foxit\fsdk_dotnet.dll</HintPath>
</Reference>

步驟 2：更新命名空間

// Before (Foxit PDF)
using foxit;
using foxit.common;
using foxit.common.fxcrt;
using foxit.pdf;
using foxit.pdf.annots;
using foxit.addon.conversion;

// After (IronPDF)
using IronPdf;
using IronPdf.Rendering;
using IronPdf.Editing;

// Before (Foxit PDF)
using foxit;
using foxit.common;
using foxit.common.fxcrt;
using foxit.pdf;
using foxit.pdf.annots;
using foxit.addon.conversion;

// After (IronPDF)
using IronPdf;
using IronPdf.Rendering;
using IronPdf.Editing;

步驟 3：初始化 IronPDF

Foxit PDF 遷移中最顯著的改進之一是消除了複雜的初始化和清理模式：

// Before (Foxit PDF)
string sn = "YOUR_SERIAL_NUMBER";
string key = "YOUR_LICENSE_KEY";
ErrorCode error_code = Library.Initialize(sn, key);
if (error_code != ErrorCode.e_ErrSuccess)
{
    throw new Exception("Failed to initialize Foxit PDF SDK");
}
// ... your code ...
Library.Release();  // Don't forget this!

// After (IronPDF)
IronPdf.License.LicenseKey = "YOUR-IRONPDF-LICENSE-KEY";
// That's it! No Release() needed

// Before (Foxit PDF)
string sn = "YOUR_SERIAL_NUMBER";
string key = "YOUR_LICENSE_KEY";
ErrorCode error_code = Library.Initialize(sn, key);
if (error_code != ErrorCode.e_ErrSuccess)
{
    throw new Exception("Failed to initialize Foxit PDF SDK");
}
// ... your code ...
Library.Release();  // Don't forget this!

// After (IronPDF)
IronPdf.License.LicenseKey = "YOUR-IRONPDF-LICENSE-KEY";
// That's it! No Release() needed

步驟 4：基本轉換模式

// Before (Foxit PDF)
Library.Initialize(sn, key);
HTML2PDFSettingData settings = new HTML2PDFSettingData();
settings.page_width = 612.0f;
settings.page_height = 792.0f;
using (HTML2PDF html2pdf = new HTML2PDF(settings))
{
    html2pdf.Convert(htmlContent, "output.pdf");
}
Library.Release();

// After (IronPDF)
var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(htmlContent);
pdf.SaveAs("output.pdf");

// Before (Foxit PDF)
Library.Initialize(sn, key);
HTML2PDFSettingData settings = new HTML2PDFSettingData();
settings.page_width = 612.0f;
settings.page_height = 792.0f;
using (HTML2PDF html2pdf = new HTML2PDF(settings))
{
    html2pdf.Convert(htmlContent, "output.pdf");
}
Library.Release();

// After (IronPDF)
var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf(htmlContent);
pdf.SaveAs("output.pdf");

命名空間映射

核心類別映射

PDFDoc 方法

HTML2PDF轉換

水印設定

範例 1：HTML 轉 PDF

（Foxit PDF SDK 之前）：

// NuGet: Install-Package Foxit.SDK
using Foxit.SDK;
using Foxit.SDK.Common;
using Foxit.SDK.PDFConversion;
using System;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        HTML2PDFSettingData settingData = new HTML2PDFSettingData();
        settingData.page_width = 612.0f;
        settingData.page_height = 792.0f;
        settingData.page_mode = HTML2PDFPageMode.e_HTML2PDFPageModeSinglePage;

        using (HTML2PDF html2pdf = new HTML2PDF(settingData))
        {
            html2pdf.Convert("<html><body><h1>Hello World</h1></body></html>", "output.pdf");
        }

        Library.Release();
    }
}

// NuGet: Install-Package Foxit.SDK
using Foxit.SDK;
using Foxit.SDK.Common;
using Foxit.SDK.PDFConversion;
using System;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        HTML2PDFSettingData settingData = new HTML2PDFSettingData();
        settingData.page_width = 612.0f;
        settingData.page_height = 792.0f;
        settingData.page_mode = HTML2PDFPageMode.e_HTML2PDFPageModeSinglePage;

        using (HTML2PDF html2pdf = new HTML2PDF(settingData))
        {
            html2pdf.Convert("<html><body><h1>Hello World</h1></body></html>", "output.pdf");
        }

        Library.Release();
    }
}

（IronPDF 之後）：

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderHtmlAsPdf("<html><body><h1>Hello World</h1></body></html>");
        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("<html><body><h1>Hello World</h1></body></html>");
        pdf.SaveAs("output.pdf");
    }
}

IronPDF 方法將 15 行以上的配置程式碼減少到僅 4 行。 無需庫初始化，無需明確清理，無需複雜的設定物件。 如需更多 HTML 渲染選項，請參閱HTML 轉 PDF 文件。

範例 2：URL 轉 PDF

（Foxit PDF SDK 之前）：

// NuGet: Install-Package Foxit.SDK
using Foxit.SDK;
using Foxit.SDK.Common;
using Foxit.SDK.PDFConversion;
using System;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        HTML2PDFSettingData settingData = new HTML2PDFSettingData();
        settingData.page_width = 612.0f;
        settingData.page_height = 792.0f;
        settingData.page_mode = HTML2PDFPageMode.e_HTML2PDFPageModeSinglePage;

        using (HTML2PDF html2pdf = new HTML2PDF(settingData))
        {
            html2pdf.ConvertFromURL("https://www.example.com", "output.pdf");
        }

        Library.Release();
    }
}

// NuGet: Install-Package Foxit.SDK
using Foxit.SDK;
using Foxit.SDK.Common;
using Foxit.SDK.PDFConversion;
using System;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        HTML2PDFSettingData settingData = new HTML2PDFSettingData();
        settingData.page_width = 612.0f;
        settingData.page_height = 792.0f;
        settingData.page_mode = HTML2PDFPageMode.e_HTML2PDFPageModeSinglePage;

        using (HTML2PDF html2pdf = new HTML2PDF(settingData))
        {
            html2pdf.ConvertFromURL("https://www.example.com", "output.pdf");
        }

        Library.Release();
    }
}

（IronPDF 之後）：

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");
        pdf.SaveAs("output.pdf");
    }
}

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

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");
        pdf.SaveAs("output.pdf");
    }
}

IronPDF 內建的 Chromium 引擎可自動處理 JavaScript 執行、CSS 渲染和動態內容。 了解更多關於URL轉PDF的資訊。

範例 3：添加浮水印

（Foxit PDF SDK 之前）：

// NuGet: Install-Package Foxit.SDK
using Foxit.SDK;
using Foxit.SDK.Common;
using Foxit.SDK.PDFDoc;
using System;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        using (PDFDoc doc = new PDFDoc("input.pdf"))
        {
            doc.Load("");

            Watermark watermark = new Watermark(doc, "Confidential", 
                new Font(Font.StandardID.e_StdIDHelvetica), 48.0f, 0xFF0000FF);

            WatermarkSettings settings = new WatermarkSettings();
            settings.flags = Watermark.e_WatermarkFlagASPageContents;
            settings.position = Watermark.Position.e_PosCenter;
            settings.rotation = -45.0f;
            settings.opacity = 0.5f;

            watermark.SetSettings(settings);
            watermark.InsertToAllPages();

            doc.SaveAs("output.pdf", PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
        }

        Library.Release();
    }
}

// NuGet: Install-Package Foxit.SDK
using Foxit.SDK;
using Foxit.SDK.Common;
using Foxit.SDK.PDFDoc;
using System;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        using (PDFDoc doc = new PDFDoc("input.pdf"))
        {
            doc.Load("");

            Watermark watermark = new Watermark(doc, "Confidential", 
                new Font(Font.StandardID.e_StdIDHelvetica), 48.0f, 0xFF0000FF);

            WatermarkSettings settings = new WatermarkSettings();
            settings.flags = Watermark.e_WatermarkFlagASPageContents;
            settings.position = Watermark.Position.e_PosCenter;
            settings.rotation = -45.0f;
            settings.opacity = 0.5f;

            watermark.SetSettings(settings);
            watermark.InsertToAllPages();

            doc.SaveAs("output.pdf", PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
        }

        Library.Release();
    }
}

（IronPDF 之後）：

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

class Program
{
    static void Main()
    {
        var pdf = PdfDocument.FromFile("input.pdf");
        pdf.ApplyWatermark(new TextStamper()
        {
            Text = "Confidential",
            FontSize = 48,
            Opacity = 50,
            Rotation = -45,
            VerticalAlignment = VerticalAlignment.Middle,
            HorizontalAlignment = HorizontalAlignment.Center
        });
        pdf.SaveAs("output.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(new TextStamper()
        {
            Text = "Confidential",
            FontSize = 48,
            Opacity = 50,
            Rotation = -45,
            VerticalAlignment = VerticalAlignment.Middle,
            HorizontalAlignment = HorizontalAlignment.Center
        });
        pdf.SaveAs("output.pdf");
    }
}

IronPDF 的TextStamper提供基於屬性的直覺配置，而不是單獨的設定物件和手動頁面迭代。 有關更多選項，請參閱完整的水印文件。

範例 4：帶有頁首和頁尾的 PDF 的 URL

（Foxit PDF SDK 之前）：

using foxit;
using foxit.addon.conversion;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        try
        {
            HTML2PDFSettingData settings = new HTML2PDFSettingData();
            settings.page_width = 595.0f;  // A4
            settings.page_height = 842.0f;
            settings.page_margin_top = 100.0f;
            settings.page_margin_bottom = 100.0f;

            // Foxit PDF SDK has limited header/footer support
            // Often requires post-processing or additional code

            using (HTML2PDF html2pdf = new HTML2PDF(settings))
            {
                html2pdf.ConvertFromURL("https://www.example.com", "webpage.pdf");
            }
        }
        finally
        {
            Library.Release();
        }
    }
}

using foxit;
using foxit.addon.conversion;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        try
        {
            HTML2PDFSettingData settings = new HTML2PDFSettingData();
            settings.page_width = 595.0f;  // A4
            settings.page_height = 842.0f;
            settings.page_margin_top = 100.0f;
            settings.page_margin_bottom = 100.0f;

            // Foxit PDF SDK has limited header/footer support
            // Often requires post-processing or additional code

            using (HTML2PDF html2pdf = new HTML2PDF(settings))
            {
                html2pdf.ConvertFromURL("https://www.example.com", "webpage.pdf");
            }
        }
        finally
        {
            Library.Release();
        }
    }
}

（IronPDF 之後）：

using IronPdf;

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
        renderer.RenderingOptions.PrintHtmlBackgrounds = true;
        renderer.RenderingOptions.WaitFor.RenderDelay(3000);  // Wait for JS

        // Built-in header/footer support
        renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter()
        {
            HtmlFragment = "<div style='text-align:center; font-size:12pt;'>Company Report</div>",
            DrawDividerLine = true
        };

        renderer.RenderingOptions.HtmlFooter = new HtmlHeaderFooter()
        {
            HtmlFragment = "<div style='text-align:right; font-size:10pt;'>Page {page} of {total-pages}</div>",
            DrawDividerLine = true
        };

        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");
        pdf.SaveAs("webpage.pdf");
    }
}

using IronPdf;

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();
        renderer.RenderingOptions.PaperSize = PdfPaperSize.A4;
        renderer.RenderingOptions.PrintHtmlBackgrounds = true;
        renderer.RenderingOptions.WaitFor.RenderDelay(3000);  // Wait for JS

        // Built-in header/footer support
        renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter()
        {
            HtmlFragment = "<div style='text-align:center; font-size:12pt;'>Company Report</div>",
            DrawDividerLine = true
        };

        renderer.RenderingOptions.HtmlFooter = new HtmlHeaderFooter()
        {
            HtmlFragment = "<div style='text-align:right; font-size:10pt;'>Page {page} of {total-pages}</div>",
            DrawDividerLine = true
        };

        var pdf = renderer.RenderUrlAsPdf("https://www.example.com");
        pdf.SaveAs("webpage.pdf");
    }
}

IronPDF 提供原生頁首和頁尾支持，支援 HTML 樣式和動態頁碼佔位符。

範例 5：PDF 安全性與加密

（Foxit PDF SDK 之前）：

using foxit;
using foxit.pdf;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        try
        {
            using (PDFDoc doc = new PDFDoc("input.pdf"))
            {
                doc.LoadW("");

                StdSecurityHandler securityHandler = new StdSecurityHandler();
                securityHandler.Initialize(
                    StdSecurityHandler.EncryptAlgorithm.e_CipherAES,
                    "user_password",
                    "owner_password",
                    PDFDoc.Permission.e_PermPrint | PDFDoc.Permission.e_PermModify,
                    128);

                doc.SetSecurityHandler(securityHandler);
                doc.SaveAs("encrypted.pdf", (int)PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
            }
        }
        finally
        {
            Library.Release();
        }
    }
}

using foxit;
using foxit.pdf;

class Program
{
    static void Main()
    {
        Library.Initialize("sn", "key");

        try
        {
            using (PDFDoc doc = new PDFDoc("input.pdf"))
            {
                doc.LoadW("");

                StdSecurityHandler securityHandler = new StdSecurityHandler();
                securityHandler.Initialize(
                    StdSecurityHandler.EncryptAlgorithm.e_CipherAES,
                    "user_password",
                    "owner_password",
                    PDFDoc.Permission.e_PermPrint | PDFDoc.Permission.e_PermModify,
                    128);

                doc.SetSecurityHandler(securityHandler);
                doc.SaveAs("encrypted.pdf", (int)PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
            }
        }
        finally
        {
            Library.Release();
        }
    }
}

（IronPDF 之後）：

using IronPdf;

class Program
{
    static void Main()
    {
        var pdf = PdfDocument.FromFile("input.pdf");

        // Set passwords
        pdf.SecuritySettings.OwnerPassword = "owner_password";
        pdf.SecuritySettings.UserPassword = "user_password";

        // Set permissions
        pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights;
        pdf.SecuritySettings.AllowUserEdits = IronPdf.Security.PdfEditSecurity.EditAll;
        pdf.SecuritySettings.AllowUserCopyPasteContent = true;
        pdf.SecuritySettings.AllowUserAnnotations = true;

        pdf.SaveAs("encrypted.pdf");
    }
}

using IronPdf;

class Program
{
    static void Main()
    {
        var pdf = PdfDocument.FromFile("input.pdf");

        // Set passwords
        pdf.SecuritySettings.OwnerPassword = "owner_password";
        pdf.SecuritySettings.UserPassword = "user_password";

        // Set permissions
        pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights;
        pdf.SecuritySettings.AllowUserEdits = IronPdf.Security.PdfEditSecurity.EditAll;
        pdf.SecuritySettings.AllowUserCopyPasteContent = true;
        pdf.SecuritySettings.AllowUserAnnotations = true;

        pdf.SaveAs("encrypted.pdf");
    }
}

重用 ChromePdfRenderer

為了在 Foxit PDF 遷移過程中獲得最佳效能，請重複使用ChromePdfRenderer實例－它是線程安全的：

// GOOD - Reuse renderer (thread-safe)
public class PdfService
{
    private static readonly ChromePdfRenderer _renderer = new ChromePdfRenderer();

    public byte[] Generate(string html) => _renderer.RenderHtmlAsPdf(html).BinaryData;
}

// BAD - Creates new instance each time
public byte[] GenerateBad(string html)
{
    var renderer = new ChromePdfRenderer();  // Wasteful
    return renderer.RenderHtmlAsPdf(html).BinaryData;
}

// GOOD - Reuse renderer (thread-safe)
public class PdfService
{
    private static readonly ChromePdfRenderer _renderer = new ChromePdfRenderer();

    public byte[] Generate(string html) => _renderer.RenderHtmlAsPdf(html).BinaryData;
}

// BAD - Creates new instance each time
public byte[] GenerateBad(string html)
{
    var renderer = new ChromePdfRenderer();  // Wasteful
    return renderer.RenderHtmlAsPdf(html).BinaryData;
}

單位換算助手

Foxit PDF SDK 使用點； IronPDF 使用毫米作為單位。 遷移過程中請使用此輔助工具：

public static class UnitConverter
{
    public static double PointsToMm(double points) => points * 0.352778;
    public static double MmToPoints(double mm) => mm / 0.352778;
    public static double InchesToMm(double inches) => inches * 25.4;
}

// Usage: Convert Foxit's 72 points (1 inch) to IronPDF millimeters
renderer.RenderingOptions.MarginTop = UnitConverter.PointsToMm(72); // ~25.4mm

public static class UnitConverter
{
    public static double PointsToMm(double points) => points * 0.352778;
    public static double MmToPoints(double mm) => mm / 0.352778;
    public static double InchesToMm(double inches) => inches * 25.4;
}

// Usage: Convert Foxit's 72 points (1 inch) to IronPDF millimeters
renderer.RenderingOptions.MarginTop = UnitConverter.PointsToMm(72); // ~25.4mm

妥善處置資源

// GOOD - Using statement for automatic cleanup
using (var pdf = PdfDocument.FromFile("large.pdf"))
{
    string text = pdf.ExtractAllText();
}  // pdf is disposed automatically

// GOOD - Using statement for automatic cleanup
using (var pdf = PdfDocument.FromFile("large.pdf"))
{
    string text = pdf.ExtractAllText();
}  // pdf is disposed automatically

問題 1：未找到 Library.Initialize()

問題： IronPDF 中不存在Library.Initialize() 。

解決方案： IronPDF 使用了更簡單的初始化模式：

// Foxit PDF
Library.Initialize(sn, key);

// IronPDF - just set license key once at startup
IronPdf.License.LicenseKey = "YOUR-KEY";

// Foxit PDF
Library.Initialize(sn, key);

// IronPDF - just set license key once at startup
IronPdf.License.LicenseKey = "YOUR-KEY";

問題 2：錯誤代碼處理

問題：程式碼檢查ErrorCode.e_ErrSuccess ，但 IronPDF 沒有這個屬性。

解決方案：使用標準的.NET異常處理：

// Foxit PDF
ErrorCode err = doc.LoadW("");
if (err != ErrorCode.e_ErrSuccess) { /* handle error */ }

// IronPDF
try
{
    var pdf = PdfDocument.FromFile("input.pdf");
}
catch (IOException ex)
{
    Console.WriteLine($"Failed to load PDF: {ex.Message}");
}

// Foxit PDF
ErrorCode err = doc.LoadW("");
if (err != ErrorCode.e_ErrSuccess) { /* handle error */ }

// IronPDF
try
{
    var pdf = PdfDocument.FromFile("input.pdf");
}
catch (IOException ex)
{
    Console.WriteLine($"Failed to load PDF: {ex.Message}");
}

問題 3：未找到 PDFDoc.Close()

問題： IronPDF 中不存在doc.Close()方法。

解決方法：使用Dispose()或using語句：

// Foxit PDF
doc.Close();

// IronPDF
pdf.Dispose();
// or better: wrap in using statement

// Foxit PDF
doc.Close();

// IronPDF
pdf.Dispose();
// or better: wrap in using statement

遷移前

• 清點所有已使用的 Foxit PDF SDK 功能
• 文件許可證密鑰位置
• 注意所有Library.Initialize()和Library.Release()調用
• 列出自訂設定（頁面大小、邊距等）
• 使用 ErrorCode 識別錯誤處理模式
• 將項目備份到版本控制系統
• 取得 IronPDF 許可證密鑰

軟體包遷移

• 從 .csproj 檔案移除 Foxit PDF SDK DLL 引用
• 刪除所有私有 NuGet 來源配置 安裝 IronPdf NuGet 套件： dotnet add package IronPdf
• 更新命名空間匯入
• 啟動時設定 IronPDF 許可證密鑰

程式碼遷移

• 移除Library.Initialize()和Library.Release()調用
• 將ErrorCode檢查替換為 try/catch 語句。
• 將PDFDoc替換為PdfDocument
• 將HTML2PDF替換為ChromePdfRenderer
• 將頁面存取權從GetPage(i)更新為Pages[i]
• 將SaveAs(path, flags)替換為SaveAs(path)
• 將Close()替換為Dispose()或 using 語句
• 更新水印程式碼，使用TextStamper
• 將單位從點轉換為毫米

測試

• 驗證 HTML 轉 PDF 輸出是否符合預期
• 測試 PDF 載入和文字擷取
• 驗證合併功能
• 檢查水印外觀
• 測試安全/加密功能
• 驗證表單欄位操作
• 效能測試

移民後

• 刪除 Foxit PDF SDK DLL 文件
• 刪除與 Foxit 相關的設定檔
• 更新文檔
• 清理未使用的輔助程式碼

遷移。