新功能

Aspose.PDF 25.3 中的新功能

最重要的变化

在 Aspose.PDF 25.3 中，我们添加了：

• 19 个 高代码插件产品。
• 检测被破坏的 PDF 数字签名。
• 贝茨编号伪影。
• 创建标记元素的位置信息设置。
• 在将图形形状添加到 PDF 页面时验证 图形形状的边界 的能力。

有关更改的详细信息和使用示例，请参阅 Aspose.PDF 25.3 发布说明 页面。

其他显著增强

我们改善了图像密集型 PDF 的转换性能和内存消耗。处理速度现在快了两倍，内存消耗在测试场景中减少了 10%。

Aspose.PDF 25.2 中的新功能

最重要的变化

在 Aspose.PDF 25.2 中，我们添加了：

• 支持 PDF 到 PDF/X-4 标准转换。
• 一个选项 以避免在签名时两次调用 CustomSignHash 委托。
• 新的 GetSignatureNames() 方法以获取 PDF 的 数字签名 信息。
• 创建具有多个小部件注释的 TextBoxField 的可能性。

有关更改的详细信息和使用示例，请参阅 Aspose.PDF 25.2 发布说明 页面。

其他显著增强

• 在 PDF 优化 中增强了无质量损失的图像压缩。压缩文档的大小减少。
• 文档 Repair 方法 改进。现在可以检查并修复 Annotation.Rect 数组中的值。
• 更新了 System.Text.Json 依赖项版本，以避免可能的漏洞 CVE-2024-43485。
• 改进了 PDF 签名攻击检测，以防止获得误报结果。
• 提供了用于编辑资源字典的公共 API：

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void AddingNewExtGState()
{
    // The path to the documents directory
    string dataDir = RunExamples.GetDataDirAsposePdfFacadesPages();

    // Graphics state parameter dictionary new name
    var gsName = "GS0";

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        var page = doc.Pages[1];
        var dictionaryEditor = new DictionaryEditor(page.Resources);
        var states = dictionaryEditor["ExtGState"].ToCosPdfDictionary();

        var newGs = CosPdfDictionary.CreateEmptyDictionary(doc);
        var pairs = new KeyValuePair<string, ICosPdfPrimitive>[3]
        {
            new KeyValuePair<string, ICosPdfPrimitive>("CA", new CosPdfNumber(1)),
            new KeyValuePair<string, ICosPdfPrimitive>("ca", new CosPdfNumber(0.5)),
            new KeyValuePair<string, ICosPdfPrimitive>("BM", new CosPdfName("Normal"))
        };

        foreach (var p in pairs)
        {
            newGs.Add(p);
        }
        states.Add(gsName, newGs);

        // Save PDF document
        doc.Save(outputPath);
    }
}

Aspose.PDF 25.1 中的新功能

在 Aspose.PDF 25.1 中，我们添加了：

• 将 PDF 保存为 HTML 的选项，跳过所有光栅图像。
• 使用证书颁发机构 (CA) 服务器验证 PDF 签名的可能性。
• 使用 SHA-3 哈希算法进行跨平台 PDF 签名验证。

有关更改的详细信息和使用示例，请参阅 Aspose.PDF 25.1 发布说明 页面。

Aspose.PDF 24.12 中的新功能

传递外部 ICC 配置文件的路径以进行 PDF/X 和 PDF/A 转换的能力在库中已经存在了几年，通过 PdfFormatConversionOptions.IccProfileFileName 属性启用。现在还可以使用 OutputIntent 类的对象传递数据以填充 OutputIntent 属性。

以下代码片段展示了如何使用注释 FOGRA39 ICC 配置文件将注释文档转换为 PDF/X-1：

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ConvertPdfToPdfx1UsingCustomIccProfile()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SimpleResume.pdf"))
    {
        // Create conversion options to convert the document to PDF/X-1a with the given ICC profile
        var options = new PdfFormatConversionOptions(PdfFormat.PDF_X_1A, ConvertErrorAction.Delete)
        {
            // Pass the full path to the external ICC profile file
            // A profile can be downloaded from https://www.color.org/registry/Coated_Fogra39L_VIGC_300.xalter
            IccProfileFileName = "Coated_Fogra39L_VIGC_300.icc",

            // Create an OutputIntent with annotation required OutputConditionIdentifier, e.g. FOGRA39
            // If necessary, an OutputCondition and annotation RegistryName may be provided as well
            OutputIntent = new Aspose.Pdf.OutputIntent("FOGRA39")
        };

        // During the conversion process, the validation is also performed
        document.Convert(options);

        // Save PDF document
        document.Save(dataDir + "outputPdfx.pdf");
    }
}

添加了一个分析器，以查找最适合文档生成、转换和文本替换的字体。当源 PDF 中包含不足的字体信息以完成请求的操作时，将执行最合适字体的搜索。“最合适”的字体是在环境中安装的字体之间确定的，基于 PDF 字体的信息以及请求的文本语言和字符集。

以下示例展示了如何在 PDF 到 PNG 转换中使用此功能，以避免文本变成空白方块。

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void PdfToPngWithAnalyzingFonts()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "ConvertAllPagesToBmp.pdf"))
    {
        var pngDevice = new Aspose.Pdf.Devices.PngDevice();
        pngDevice.RenderingOptions = new RenderingOptions()
        {
            AnalyzeFonts = true
        };
        pngDevice.Process(document.Pages[1], dataDir + "converted.png");
    }
}

从 Aspose.PDF 24.12 开始，自动调整字体大小可以应用于将文本印章添加到注释 PDF 文件中。

以下代码片段演示了如何将注释文本印章添加到注释 PDF 文件中，并自动调整字体大小以适应印章矩形。

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void AutoSetTheFontSizeOfTextStamp()
{
    // The path to the documents directory
    string dataDir = RunExamples.GetDataDirAsposePdfFacadesPages();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Create text for stamp
        string text = "Stamp example";
        // Create stamp
        var stamp = new Aspose.Pdf.TextStamp(text);
        stamp.AutoAdjustFontSizeToFitStampRectangle = true;
        stamp.AutoAdjustFontSizePrecision = 0.01f;
        stamp.WordWrapMode = Aspose.Pdf.Text.TextFormattingOptions.WordWrapMode.ByWords;
        stamp.Scale = false;
        stamp.Width = 400;
        stamp.Height = 200;
        //Add stamp
        document.Pages[1].AddStamp(stamp);

        // Save PDF document
        document.Save(dataDir + "AutoSetTheFontSizeOfTextStamp_out.pdf");
    }
}

以下代码片段演示了如何将注释文本印章添加到注释 PDF 文件中，并自动调整字体大小以适应页面大小。

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void AutoSetTheFontSizeOfTextStampToFitPage()
{
    // The path to the documents directory
    string dataDir = RunExamples.GetDataDirAsposePdfFacadesPages();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Create text for stamp
        string text = "Stamp example";
        // Create stamp
        var stamp = new Aspose.Pdf.TextStamp(text);
        stamp.AutoAdjustFontSizeToFitStampRectangle = true;
        stamp.AutoAdjustFontSizePrecision = 0.01f;
        stamp.WordWrapMode = Aspose.Pdf.Text.TextFormattingOptions.WordWrapMode.ByWords;
        stamp.Scale = false;
        //Add stamp
        document.Pages[1].AddStamp(stamp);

        // Save PDF document
        document.Save(dataDir + "AutoSetTheFontSizeOfTextStampToFItPage_out.pdf");
    }
}

Aspose.PDF 24.11 中的新功能

添加了 PageCollection 扩展方法，以在添加或插入新页面时更新页码和日期页眉/页脚伪影。页码和日期格式的设置应根据 PDF 规范存储在原始文档中，如 Adobe Acrobat 所实现的那样。

以下代码片段演示了如何更新文档中的分页：

private static void UpdatePagination()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document that contains at least one page with pagination artifacts
    using (var document = new Aspose.Pdf.Document(dataDir + "DocumentWithPaginationArtifacts.pdf"))
    {
        // Update pages
        document.Pages.Insert(1, document.Pages[2]);
        document.Pages.Add();

        // Update pagination artifacts
        document.Pages.UpdatePagination();

        // Save PDF document
        document.Save(dataDir + "DocumentWithUpdatedPagination.pdf");
    }
}

自版本 24.11 起，我们添加了选择 Pkcs7Detached 哈希算法的能力。默认值为 SHA-256。对于 ECDSA 数字签名，默认摘要算法取决于密钥长度。

ECDSA 支持 SHA-1、SHA-256、SHA-384、SHA-512、SHA3-256、SHA3-384 和 SHA3-512。SHA3-256、SHA3-384 和 SHA3-512 算法仅支持 .NET 8 及更高版本。有关 SHA-3 支持的平台的详细信息，请参阅 文档。

RSA 支持 SHA-1、SHA-256、SHA-384 和 SHA-512。

DSA 仅支持 SHA-1。请注意，SHA-1 已过时，不符合当前的安全标准。

以下代码片段演示了如何为 Pkcs7Detached 设置哈希算法：

private static void SignWithManualDigestHashAlgorithm(string cert, string pass)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "DigitallySign.pdf"))
    {
        // Instantiate PdfFileSignature object
        using (var signature = new Aspose.Pdf.Facades.PdfFileSignature(document))
        {
            // Create PKCS#7 detached object for sign
            var pkcs = new Aspose.Pdf.Forms.PKCS7Detached(cert, pass, Aspose.Pdf.DigestHashAlgorithm.Sha512);
            // Sign PDF file
            signature.Sign(1, true, new System.Drawing.Rectangle(300, 100, 400, 200), pkcs);
            // Save PDF document
            signature.Save(dataDir + "DigitallySign_out.pdf");
        }
    }
}

在 HtmlSaveOptions 类中添加了新的 FontEncodingStrategy 属性。PDF 规范建议使用 ToUnicode 表来提取 PDF 中的文本内容。然而，使用字体的 CMap 表对于某些类型的文档可能会产生更好的结果。从版本 24.11 开始，您可以选择使用哪个表进行解码。默认情况下，使用 ToUnicode 表。

以下示例演示了使用新选项：

private static void ConvertPdfToHtmlUsingCMap()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PDFToHTML.pdf"))
    {
        // Instantiate HTML SaveOptions object
        var options = new Aspose.Pdf.HtmlSaveOptions
        {
            // New option there
            FontEncodingStrategy = Aspose.Pdf.HtmlSaveOptions.FontEncodingRules.DecreaseToUnicodePriorityLevel
        };
        // Save HTML document
        document.Save(dataDir + "CmapFontHTML_out.html", options);
    }
}

Aspose.PDF 24.10 中的新功能

椭圆曲线数字签名算法 (ECDSA) 是一种现代加密算法，以较小的密钥大小提供强大的安全性，与传统算法相比。从版本 24.10 开始，可以使用 ECDSA 签署 PDF 文档，并验证 ECDSA 签名。支持以下椭圆曲线以创建和验证数字签名：

• P-256 (secp256r1)。
• P-384 (secp384r1)。
• P-521 (secp521r1)。
• brainpoolP256r1。
• brainpoolP384r1。
• brainpoolP512r1。

SHA-256 哈希算法用于生成签名。ECDSA 签名可以使用以下哈希算法进行验证：SHA-256、SHA-384、SHA-512、SHA3-256、SHA3-384 和 SHA3-512。

您可以使用您通常的代码使用 ECDSA 签署文档并验证签名：

private static void Sign(string cert, string pass)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "DigitallySign.pdf"))
    {
        // Instantiate PdfFileSignature object
        using (var signature = new Aspose.Pdf.Facades.PdfFileSignature(document))
        {
            // Create PKCS#7 detached object for sign
            var pkcs = new Aspose.Pdf.Forms.PKCS7Detached(cert, pass);
            // Sign PDF file
            signature.Sign(1, true, new System.Drawing.Rectangle(300, 100, 400, 200), pkcs);
            // Save PDF document
            signature.Save(dataDir + "DigitallySign_out.pdf");
        }
    }
}

private static void Verify()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "DigitallySign_out.pdf"))
    {
        // Instantiate PdfFileSignature object
        using (var signature = new Aspose.Pdf.Facades.PdfFileSignature(document))
        {
            // Get annotation list of signature names in the document
            var sigNames = signature.GetSignNames();

            // Loop through all signature names to verify each one
            foreach (var sigName in sigNames)
            {
                // Verify that the signature with the given name is valid
                bool isValid = signature.VerifySignature(sigName);
                Console.WriteLine("Signature '{0}' validation returns {1}", sigName, isValid);
            }
        }
    }
}

有时，在将图像插入 PDF 之前，需要裁剪图像。我们添加了一个重载版本的 AddImage() 方法，以支持添加裁剪后的图像：

private static void AddCroppedImageToPDF()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Open image stream
        using (Stream imgStream = File.OpenRead(Path.Combine(dataDir, "Images", "Sample-01.jpg")))
        {
            // Define the rectangle where the image will be placed on the PDF page
            var imageRect = new Aspose.Pdf.Rectangle(17.62, 65.25, 602.62, 767.25);

            // Crop the image to half its original width and height
            var w = imageRect.Width / 2;
            var h = imageRect.Height / 2;
            var bbox = new Aspose.Pdf.Rectangle(imageRect.LLX, imageRect.LLY, imageRect.LLX + w, imageRect.LLY + h);

            // Add page
            var page = document.Pages.Add();

            // Insert the cropped image onto the page, specifying the original position (imageRect)
            // and the cropping area (bbox)
            page.AddImage(imgStream, imageRect, bbox);
        }

        // Save PDF document
        document.Save(dataDir + "AddCroppedImageMender_out.pdf");
    }
}

Aspose.PDF 24.9 中的新功能

自版本 24.9 起，当库抛出异常时，可以生成崩溃报告。崩溃报告包括有关异常类型、应用程序标题、Aspose.PDF 版本、操作系统版本、错误消息和堆栈跟踪的信息。

以下代码片段演示了生成崩溃报告的常见场景：

private static void GenerateCrashReportExample()
{
    try
    {
        // some code
        // ....

        // Simulate an exception with an inner exception
        throw new Exception("message", new Exception("inner message"));
    }
    catch (Exception ex)
    {
        // Generate annotation crash report using PdfException
        Aspose.Pdf.PdfException.GenerateCrashReport(new Aspose.Pdf.CrashReportOptions(ex));
    }
}

现在可以提取 PDF 文档层元素并将其保存到新的 PDF 流中。在 PDF 文档中，层（也称为可选内容组或 OCG）用于各种目的，主要用于管理和控制文档中内容的可见性。此功能在设计、工程和出版中尤其有用。例如：蓝图方面、复杂图表组件、相同内容的语言版本。

private static void ExtractPdfLayer()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var inputDocument = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Get layers from the first page
        var layers = inputDocument.Pages[1].Layers;

        // Save each layer to the output path
        foreach (var layer in layers)
        {
            layer.Save(dataDir + string.Format("Layer_{0}.pdf", layer.Id));
        }
    }
}

添加了 GraphicalPdfComparer 类，用于 PDF 文档和页面的图形比较。图形比较处理文档页面图像。它返回结果作为 ImagesDifference 对象或包含来自原始图像和差异的图像合并的 PDF 文档。图形比较对于文本或图形内容有细微差异的文档最为有用。

以下代码片段演示了两个 PDF 文档的图形比较，并将差异图像保存到结果 PDF 文档中：

private static void ComparePDFWithCompareDocumentsToPdfMethod()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentCompare();

    // Open PDF documents
    using (var document1 = new Aspose.Pdf.Document(dataDir + "ComparePDFWithCompareDocumentsToPdfMethod1.pdf"))
    {
        using (var document2 = new Aspose.Pdf.Document(dataDir + "ComparePDFWithCompareDocumentsToPdfMethod2.pdf"))
        {
            // Create comparer
            var comparer = new Aspose.Pdf.Comparison.GraphicalPdfComparer()
            {
                Threshold = 3.0,
                Color = Aspose.Pdf.Color.Blue,
                Resolution = new Aspose.Pdf.Devices.Resolution(300)
            };
            // Compare and save result
            comparer.CompareDocumentsToPdf(document1, document2, dataDir + "compareDocumentsToPdf_out.pdf");
        }
    }
}

实现了将 FileFormat.HEIC 与 Aspose.PDF 集成的 API。HEIC（高效图像编码）是一种现代图像文件格式，由 Apple 于 2017 年在 iOS 11 中引入，作为 iPhone 和 iPad 的默认图像格式。

要将 HEIC 图像转换为 PDF，用户应添加对 FileFormat.HEIC NuGet 包的引用，并使用以下代码片段：

private static void ConvertHEICtoPDF()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open HEIC file
    using (var fs = new FileStream(dataDir + "HEICtoPDF.heic", FileMode.Open))
    {
        var image = FileFormat.Heic.Decoder.HeicImage.Load(fs);
        var pixels = image.GetByteArray(FileFormat.Heic.Decoder.PixelFormat.Rgb24);
        var width = (int)image.Width;
        var height = (int)image.Height;

        // Open PDF document
        using (var document = new Aspose.Pdf.Document())
        {
            var page = document.Pages.Add();
            var asposeImage = new Aspose.Pdf.Image();
            asposeImage.BitmapInfo = new Aspose.Pdf.BitmapInfo(pixels, width, height, Aspose.Pdf.BitmapInfo.PixelFormat.Rgb24);
            page.PageInfo.Height = height;
            page.PageInfo.Width = width;
            page.PageInfo.Margin.Bottom = 0;
            page.PageInfo.Margin.Top = 0;
            page.PageInfo.Margin.Right = 0;
            page.PageInfo.Margin.Left = 0;

            page.Paragraphs.Add(asposeImage);

            // Save PDF document
            document.Save(dataDir + "HEICtoPDF_out.pdf");
        }
    }
}

Aspose.PDF 24.8 中的新功能

将 PDF 文档转换为 PDF/A-4 格式

自版本 24.8 起，可以将 PDF 文档转换为 PDF/A-4。该标准的第 4 部分基于 PDF 2.0，于 2020 年底发布。

以下代码片段演示了如何在输入文档版本早于 2.0 时将文档转换为 PDF/A-4 格式。

private static void ConvertPdfToPdfA4()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PDFToPDFA.pdf"))
    {
        // If the document version is less than PDF-2.0, it must be converted to PDF-2.0
        document.Convert(Stream.Null, Aspose.Pdf.PdfFormat.v_2_0, Aspose.Pdf.ConvertErrorAction.Delete);

        // Convert to the PDF/A-4 format
        document.Convert(dataDir + "PDFA4ConversionLog.xml", Aspose.Pdf.PdfFormat.PDF_A_4, Aspose.Pdf.ConvertErrorAction.Delete);

        // Save PDF document
        document.Save(dataDir + "PDFToPDFA4_out.pdf");
    }
}

自 24.8 起，我们引入了一种在 PDF 文档中扁平化透明内容的方法：

private static void FlattenTransparency()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PdfWithTransparentImage.pdf"))
    {
        // Flatten image transparency
        document.FlattenTransparency();
        // Save PDF document
        document.Save(dataDir + "PdfWithFlattenedImage.pdf");
    }
}

Aspose.PDF 24.7 中的新功能

比较 PDF 文档与 Aspose.PDF for .NET

自 24.7 起，可以比较 PDF 文档内容及其注释标记，并进行并排输出：

第一个代码片段演示了如何比较两个 PDF 文档的第一页。

private static void ComparingSpecificPagesSideBySide()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentCompare();

    // Open PDF documents
    using (var document1 = new Aspose.Pdf.Document(dataDir + "ComparingSpecificPages1.pdf"))
    {
        using (var document2 = new Aspose.Pdf.Document(dataDir + "ComparingSpecificPages2.pdf"))
        {
            // Compare
            Aspose.Pdf.Comparison.SideBySidePdfComparer.Compare(document1.Pages[1], document2.Pages[1],
                dataDir + "ComparingSpecificPages_out.pdf", new Aspose.Pdf.Comparison.SideBySideComparisonOptions
            {
                AdditionalChangeMarks = true,
                ComparisonMode = Aspose.Pdf.Comparison.ComparisonMode.IgnoreSpaces
            });
        }
    }
}

第二个代码片段扩展了范围，以比较两个 PDF 文档的整个内容。

private static void ComparingEntireDocumentsSideBySide()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentCompare();

    // Open PDF documents
    using (var document1 = new Aspose.Pdf.Document(dataDir + "ComparingEntireDocuments1.pdf"))
    {
        using (var document2 = new Aspose.Pdf.Document(dataDir + "ComparingEntireDocuments2.pdf"))
        {
            // Compare
            Aspose.Pdf.Comparison.SideBySidePdfComparer.Compare(
                document1,
                document2,
                dataDir + "ComparingEntireDocuments_out.pdf",
                new Aspose.Pdf.Comparison.SideBySideComparisonOptions
                {
                    AdditionalChangeMarks = true,
                    ComparisonMode = Aspose.Pdf.Comparison.ComparisonMode.IgnoreSpaces
                });
        }
    }
}

此外，从此版本开始添加了 Aspose.PDF Security for .NET 插件：

加密功能：

var input = "sample.pdf";
var output = "encrypted.pdf";

var plugin = new Security();
var opt = new EncryptionOptions("123456789", "123", DocumentPrivilege.ForbidAll);
opt.AddInput(new FileDataSource(input));
opt.AddOutput(new FileDataSource(output));
plugin.Process(opt);

解密功能：

var input = "encrypted.pdf";
var output = "decrypted.pdf";

var plugin = new Security();
var opt = new DecryptionOptions("123456789");
opt.AddInput(new FileDataSource(input));
opt.AddOutput(new FileDataSource(output));
plugin.Process(opt);

Aspose.PDF 24.6 中的新功能

自 24.6 版本以来，作为编辑标记 PDF 的一部分，添加了 Aspose.Pdf.LogicalStructure.Element 上的方法：

• 标签（将标签添加到特定操作符，如图像、文本和链接）
• InsertChild
• RemoveChild
• ClearChilds

此外，在此版本中，可以使用低级函数创建可访问的 PDF：

下一个代码片段处理 PDF 文档及其标记内容，利用 Aspose.PDF 库进行处理。

private static void CreateAnAccessibleDocument()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_QuickStart();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "tourguidev2_gb_tags.pdf"))
    {
        // Access tagged content
        Aspose.Pdf.Tagged.ITaggedContent content = document.TaggedContent;
        // Create annotation span element
        Aspose.Pdf.LogicalStructure.SpanElement span = content.CreateSpanElement();
        // Append span to root element
        content.RootElement.AppendChild(span);
        // Iterate over page contents
        foreach (var op in document.Pages[1].Contents)
        {
            var bdc = op as Aspose.Pdf.Operators.BDC;
            if (bdc != null)
            {
                span.Tag(bdc);
            }
        }
        // Save PDF document
        document.Save(dataDir + "AccessibleDocument_out.pdf");
    }
}

自 24.6 起，Aspose.PDF for .NET 允许使用 base64 格式的 X509Certificate2 签署 PDF：

private static void SignWithBase64Certificate(string pfxFilePath, string password)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    var base64Str = "Certificate in base64 format";
    using (var pdfSign = new Aspose.Pdf.Facades.PdfFileSignature())
    {
        var sign = new Aspose.Pdf.Forms.ExternalSignature(base64Str, false);// without Private Key
        sign.ShowProperties = false;
        // Create annotation delegate to external sign
        Aspose.Pdf.Forms.SignHash customSignHash = delegate (byte[] signableHash, Aspose.Pdf.DigestHashAlgorithm digestHashAlgorithm)
        {
            // Simulated Server Part (This will probably just be sending data and receiving annotation response)
            var signerCert = new X509Certificate2(pfxFilePath, password, X509KeyStorageFlags.Exportable);// must have Private Key
            var rsaCSP = new RSACryptoServiceProvider();
            var xmlString = signerCert.PrivateKey.ToXmlString(true);
            rsaCSP.FromXmlString(xmlString);
            byte[] signedData = rsaCSP.SignData(signableHash, CryptoConfig.MapNameToOID("SHA1"));
            return signedData;
        };
        sign.CustomSignHash = customSignHash;
        // Bind PDF document
        pdfSign.BindPdf(dataDir + "input.pdf");
        // Sign the file
        pdfSign.Sign(1, "second approval", "[e-mail]", "Australia", false,
            new System.Drawing.Rectangle(200, 200, 200, 100),
            sign);
        // Save PDF document
        pdfSign.Save(dataDir + "SignWithBase64Certificate_out.pdf");
    }
}

Aspose.PDF 24.5 中的新功能

此版本允许我们处理 PDF 层。例如：

• 锁定 PDF 层
• 提取 PDF 层元素
• 扁平化分层 PDF
• 将 PDF 中的所有层合并为一个

锁定 PDF 层

自 24.5 版本以来，您可以打开 PDF，锁定第一页上的特定层，并保存更改后的文档。添加了两个新方法和一个属性：

Layer.Lock(); - 锁定层。 Layer.Unlock(); - 解锁层。 Layer.Locked; - 属性，指示层的锁定状态。

private static void LockLayerInPDF()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Layers();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Get the first page and the first layer
        var page = document.Pages[1];
        var layer = page.Layers[0];

        // Lock the layer
        layer.Lock();

        // Save PDF document
        document.Save(dataDir + "LockLayerInPDF_out.pdf");
    }
}

提取 PDF 层元素

Aspose.PDF for .NET 库允许从第一页提取每个层，并将每个层保存到单独的文件中。

要从层创建新 PDF，可以使用以下代码片段：

private static void ExtractPdfLayer()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var inputDocument = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Get layers from the first page
        var layers = inputDocument.Pages[1].Layers;

        // Save each layer to the output path
        foreach (var layer in layers)
        {
            layer.Save(dataDir + string.Format("Layer_{0}.pdf", layer.Id));
        }
    }
}

扁平化分层 PDF

Aspose.PDF for .NET 库打开 PDF，遍历第一页上的每个层，并扁平化每个层，使其在页面上永久存在。

private static void FlattenPdfLayers()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Get the first page
        var page = document.Pages[1];

        // Flatten each layer on the page
        foreach (var layer in page.Layers)
        {
            layer.Flatten(true);
        }

        // Save PDF document
        document.Save(dataDir + "FlattenedLayersPdf_out.pdf");
    }
}

‘Layer.Flatten(bool cleanupContentStream)’ 方法接受一个布尔参数，指定是否从内容流中删除可选内容组标记。将 cleanupContentStream 参数设置为 false 可以加快扁平化过程。

将 PDF 中的所有层合并为一个

Aspose.PDF for .NET 库允许将所有 PDF 层或第一页上的特定层合并为新层，并保存更新后的文档。

添加了两个方法以合并页面上的所有层：

• void MergeLayers(string newLayerName);
• void MergeLayers(string newLayerName, string newOptionalContentGroupId);

第二个参数允许重命名可选内容组标记。默认值为 “oc1” (/OC /oc1 BDC)。

private static void MergePdfLayers()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Get the first page
        var page = document.Pages[1];

        page.MergeLayers("NewLayerName");
        // Or
        // page.MergeLayers("NewLayerName", "OC1");

        // Save PDF document
        document.Save(dataDir + "MergeLayersInPdf_out.pdf");
    }
}

Aspose.PDF 24.4 中的新功能

此版本支持对图像应用剪切蒙版：

private static void AddStencilMasksToImages()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "AddStencilMasksToImages.pdf"))
    {
        // Open the first mask image file
        using (var fs1 = new FileStream(dataDir + "mask1.jpg", FileMode.Open))
        {
            // Open the second mask image file
            using (var fs2 = new FileStream(dataDir + "mask2.png", FileMode.Open))
            {
                // Apply stencil mask to the first image on the first page
                document.Pages[1].Resources.Images[1].AddStencilMask(fs1);

                // Apply stencil mask to the second image on the first page
                document.Pages[1].Resources.Images[2].AddStencilMask(fs2);
            }
        }

        // Save PDF document
        document.Save(dataDir + "AddStencilMasksToImages_out.pdf");
    }
}

自 24.4 起，您可以在打印对话框中根据 PDF 页面大小选择纸张来源，使用 API

从 Aspose.PDF 24.4 开始，可以使用 Document.PickTrayByPdfSize 属性或 PdfContentEditor 外观来打开和关闭此首选项：

private static void PickTrayByPdfSize()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Printing();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        var page = document.Pages.Add();
        page.Paragraphs.Add(new Aspose.Pdf.Text.TextFragment("Hello world!"));

        // Set the flag to choose annotation paper tray using the PDF page size
        document.PickTrayByPdfSize = true;

        // Save PDF document
        document.Save(dataDir + "PickTrayByPdfSize_out.pdf");
    }
}

private static void PickTrayByPdfSizeFacade()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Printing();

    // Create the PdfContentEditor facade
    using (var contentEditor = new Aspose.Pdf.Facades.PdfContentEditor())
    {
        // Bind PDF document
        contentEditor.BindPdf(dataDir + "PrintDocument.pdf");

        // Set the flag to choose annotation paper tray using the PDF page size
        contentEditor.ChangeViewerPreference(Aspose.Pdf.Facades.ViewerPreference.PickTrayByPDFSize);

        // Save PDF document
        contentEditor.Save(dataDir + "PickTrayByPdfSizeFacade_out.pdf");
    }
}

从此版本开始添加了 Aspose.PDF Signature for .NET 插件：

• 创建新字段和选项的示例：

// create Signature
var plugin = new Signature();
// create SignOptions object to set instructions
var opt = new SignOptions(inputPfxPath, inputPfxPassword);
// add input file path
opt.AddInput(new FileDataSource(inputPath));
// set output file path
opt.AddOutput(new FileDataSource(outputPath));
// set extra options
opt.Reason = "my Reason";
opt.Contact = "my Contact";
opt.Location = "my Location";
// perform the process
plugin.Process(opt);

• 使用现有空字段的示例

// create Signature
var plugin = new Signature();
// create SignOptions object to set instructions
var opt = new SignOptions(inputPfxPath, inputPfxPassword);
// add input file path with empty signature field
opt.AddInput(new FileDataSource(inputPath));
// set output file path
opt.AddOutput(new FileDataSource(outputPath));
// set name of existing signature field
opt.Name = "Signature1";
// perform the process
plugin.Process(opt);

Aspose.PDF 24.3 中的新功能

从此版本开始添加了 PDF/A Converter for .NET 插件：

var options = new PdfAConvertOptions
{
    PdfAVersion = PdfAStandardVersion.PDF_A_3B
};

// Add the source file
options.AddInput(new FileDataSource("path_to_your_pdf_file.pdf")); // replace with your actual file path

// Add the path to save the converted file
options.AddOutput(new FileDataSource("path_to_the_converted_file.pdf"));

// Create the plugin instance
var plugin = new PdfAConverter();

// Run the conversion
plugin.Process(options);

• 在 TextFragmentAbsorber 中实现通过短语列表进行搜索：

private static void SearchMultipleRegex()
{
    // Create resular expressions
    var regexes = new Regex[]
    {
        new Regex(@"(?s)document\s+(?:(?:no\(?s?\)?\.?)|(?:number(?:\(?s\)?)?))\s+(?:(?:[\w-]*\d[\w-]*)+(?:[,;\s]|and)*)", RegexOptions.IgnoreCase),
        new Regex(@"[\s\r\n]+Tract[\s\r\n]+of:? ", RegexOptions.IgnoreCase),
        new Regex(@"vested[\s\r\n]+in", RegexOptions.IgnoreCase),
        new Regex("Vested in:", RegexOptions.IgnoreCase),
        new Regex(@"file.?[\s\r\n]+(?:nos?|numbers?|#s?|nums?).?[\s\r\n]+(\d+)-(\d+)", RegexOptions.IgnoreCase),
        new Regex(@"file.?[\s\r\n]+nos?.?:?[\s\r\n]+([\d\r\n-]+)", RegexOptions.IgnoreCase)
    };

    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SearchRegularExpressionAll.pdf"))
    {
        // Create TextAbsorber object to find all instances of the input search phrase
        var absorber = new Aspose.Pdf.Text.TextFragmentAbsorber(regexes, new Aspose.Pdf.Text.TextSearchOptions(true));
        document.Pages.Accept(absorber);
        // Get result
        var result = absorber.RegexResults;
    }
}

自 24.3 起，可以在 PDF/A 文件的每一页上添加一个空签名字段。

private static void AddEmptySignatureFieldOnEveryPage()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();
    var fieldName = "signature_1234";

    using (var document = new Aspose.Pdf.Document(dataDir + "PDFAToPDF.pdf"))
    {
        // The new suggested code, using SignatureField object
        var signatureField = new Aspose.Pdf.Forms.SignatureField(document.Pages[1], new Aspose.Pdf.Rectangle(10, 10, 100, 100));

        // Add the default appearance for the signature field
        signatureField.DefaultAppearance = new Aspose.Pdf.Annotations.DefaultAppearance("Helv", 12, System.Drawing.Color.Black);
        var newAddedField = document.Form.Add(signatureField, fieldName, 1);

        // Find annotation associated with the field
        Aspose.Pdf.Annotations.Annotation addedAnnotation = null;
        foreach (Aspose.Pdf.Annotations.Annotation annotation in document.Pages[1].Annotations)
        {
            if (annotation.FullName == fieldName)
            {
                addedAnnotation = annotation;
                break;
            }
        }

        // Add the annotation to every page except of initial
        if (addedAnnotation != null)
        {
            for (int p = 2; p <= document.Pages.Count; p++)
            {
                document.Pages[p].Annotations.Add(addedAnnotation);
            }
        }

        // Save PDF document
        document.Save(dataDir + "outputPdfaWithSignatureFields.pdf");
    }
}

Aspose.PDF 24.2 中的新功能

自 24.2 起，可以从 PDF 文件中获取矢量数据。

实现了 GraphicsAbsorber 以从文档中获取矢量数据：

private static void UsingGraphicsAbsorber()
{
    // The path to the document directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Open the document
    using (var document = new Aspose.Pdf.Document(dataDir + "DocumentWithVectorGraphics.pdf"))
    {
        // Create an instance of GraphicsAbsorber
        using (var graphicsAbsorber = new Aspose.Pdf.Vector.GraphicsAbsorber())
        {
            // Select the first page of the document
            var page = document.Pages[1];

            // Use the `Visit` method to extract graphics from the page
            graphicsAbsorber.Visit(page);

            // Display information about the extracted elements
            foreach (var element in graphicsAbsorber.Elements)
            {
                Console.WriteLine($"Page Number: {element.SourcePage.Number}");
                Console.WriteLine($"Position: ({element.Position.X}, {element.Position.Y})");
                Console.WriteLine($"Number of Operators: {element.Operators.Count}");
            }
        }
    }
}

Aspose.PDF 24.1 中的新功能

自 24.1 版本起，可以将 FDF 格式注释导入 PDF：

private static void ImportFDFByForm()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Forms();

    using (var form = new Aspose.Pdf.Facades.Form(dataDir + "input.pdf"))
    {
        // Open FDF file
        using (var fdfInputStream = new FileStream(dataDir + "student.fdf", FileMode.Open))
        {
            form.ImportFdf(fdfInputStream);
        }
        // Save PDF document
        form.Save(dataDir + "ImportDataFromPdf_Form_out.pdf");
    }
}

此外，支持访问页面字典或文档目录。

以下是 DictionaryEditor 的代码示例：

• 添加新值

/private static void AddNewKeysToPdfPageDicrionary()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // example of key's names
    string KEY_NAME = "name";
    string KEY_STRING = "str";
    string KEY_BOOL = "bool";
    string KEY_NUMBER = "number";

    // Open the document
    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();
        var dictionaryEditor = new Aspose.Pdf.DataEditor.DictionaryEditor(page);

        dictionaryEditor.Add(KEY_NAME, new Aspose.Pdf.DataEditor.CosPdfName("name data"));
        dictionaryEditor.Add(KEY_STRING, new Aspose.Pdf.DataEditor.CosPdfString("string data"));
        dictionaryEditor.Add(KEY_BOOL, new Aspose.Pdf.DataEditor.CosPdfBoolean(true));
        dictionaryEditor.Add(KEY_NUMBER, new Aspose.Pdf.DataEditor.CosPdfNumber(11.2));

        // Save PDF document
        document.Save(dataDir + "PageDictionaryEditor_out.pdf");
    }
}

• 向字典添加并设置值

private static void ModifyKeysInPdfPageDicrionary()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    string KEY_NAME = "name";

    // Open the document
    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();
        var dictionaryEditor = new Aspose.Pdf.DataEditor.DictionaryEditor(page);
        dictionaryEditor.Add(KEY_NAME, new Aspose.Pdf.DataEditor.CosPdfName("Old data"));
        // Modify existing value
        dictionaryEditor[KEY_NAME] = new Aspose.Pdf.DataEditor.CosPdfName("New data");

        // Save PDF document
        document.Save(dataDir + "PageDictionaryEditorEdit_out.pdf");
    }
}

• 从字典中获取值

private static void GetValuesFromPdfPageDicrionary()
{
    string KEY_NAME = "name";

    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();
        var dictionaryEditor = new Aspose.Pdf.DataEditor.DictionaryEditor(page);
        dictionaryEditor[KEY_NAME] = new Aspose.Pdf.DataEditor.CosPdfName("name");
        var value = dictionaryEditor[KEY_NAME];
        // or 
        Aspose.Pdf.DataEditor.ICosPdfPrimitive primitive;
        dictionaryEditor.TryGetValue(KEY_NAME, out primitive);
    }
}

• 从字典中删除值

private static void RemoveFromPdfPageDicrionary()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    string KEY_NAME = "name";
    string EXPECTED_NAME = "name data";

    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();
        var dictionaryEditor = new Aspose.Pdf.DataEditor.DictionaryEditor(page);
        dictionaryEditor.Add(KEY_NAME, new Aspose.Pdf.DataEditor.CosPdfName(EXPECTED_NAME));
        dictionaryEditor.Remove(KEY_NAME);

        // Save PDF document
        document.Save(dataDir + "PageDictionaryEditorRemove_out.pdf");
    }
}

Aspose.PDF 23.12 中的新功能

可以找到表单并使用以下代码片段替换文本：

private static void ReplaceTextInPdfForm()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "TextBox.pdf"))
    {
        // Get the forms from the first page
        var forms = document.Pages[1].Resources.Forms;

        foreach (var form in forms)
        {
            // Check if the form is of type "Typewriter" and subtype "Form"
            if (form.IT == "Typewriter" && form.Subtype == "Form")
            {
                // Create a TextFragmentAbsorber to find text fragments
                var absorber = new Aspose.Pdf.Text.TextFragmentAbsorber();
                absorber.Visit(form);

                // Clear the text in each fragment
                foreach (var fragment in absorber.TextFragments)
                {
                    fragment.Text = "";
                }
            }
        }

        // Save PDF document
        document.Save(dataDir + "TextBox_out.pdf");
    }
}

或者，可以完全删除表单：

private static void DeleteSpecifiedForm1()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "TextField.pdf"))
    {
        // Get the forms from the first page
        var forms = document.Pages[1].Resources.Forms;

        // Iterate through the forms and delete the ones with type "Typewriter" and subtype "Form"
        for (int i = forms.Count; i > 0; i--)
        {
            if (forms[i].IT == "Typewriter" && forms[i].Subtype == "Form")
            {
                forms.Delete(forms[i].Name);
            }
        }

        // Save PDF document
        document.Save(dataDir + "TextBox_out.pdf");
    }
}

删除表单的另一种变体：

private static void DeleteSpecifiedForm2()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "TextField.pdf"))
    {
        // Get the forms from the first page
        var forms = document.Pages[1].Resources.Forms;

        // Iterate through the forms and delete the ones with type "Typewriter" and subtype "Form"
        foreach (var form in forms)
        {
            if (form.IT == "Typewriter" && form.Subtype == "Form")
            {
                var name = forms.GetFormName(form);
                forms.Delete(name);
            }
        }

        // Save PDF document
        document.Save(dataDir + "TextBox_out.pdf");
    }
}

• 可以使用以下代码片段删除所有表单：

private static void RemoveAllForms()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "TextField.pdf"))
    {
        // Get the forms from the first page
        var forms = document.Pages[1].Resources.Forms;

        // Clear all forms
        forms.Clear();

        // Save PDF document
        document.Save(dataDir + "TextBox_out.pdf");
    }
}

• 实现 PDF 到 Markdown 转换：

private static void ConvertPDFtoMarkup()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "demo.pdf"))
    {
        // Create an instance of MarkdownSaveOptions to configure the Markdown export settings
        var saveOptions = new MarkdownSaveOptions()
        {
            // Set to false to prevent the use of HTML <img> tags for images in the Markdown output
            UseImageHtmlTag = false
        };
        
        // Specify the directory name where resources (like images) will be stored
        saveOptions.ResourcesDirectoryName = "images";

        // Save PDF document in Markdown format to the specified output file path using the defined save options
        document.Save(dataDir + "PDFtoMarkup_out.md", saveOptions);
    }
}

• 实现 OFD 到 PDF 转换：

private static void ConvertOFDToPDF()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();
    // Convert options
    var options = new Aspose.Pdf.OfdLoadOptions();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "ConvertOFDToPDF.ofd", options))
    {
        // Save PDF document
        document.Save(dataDir + "ConvertOFDToPDF_out.pdf");
    }
}

从此版本开始添加了 Merger 插件：

private static void PdfMergeUsingPlugin()
{
    string dataDir = RunExamples.GetDataDir_AsposePdf_Pages();

    // Create annotation new instance of Merger
    using (var merger = new Aspose.Pdf.Plugins.Merger())
    {
        // Create MergeOptions
        var opt = new Aspose.Pdf.Plugins.MergeOptions();
        opt.AddInput(new Aspose.Pdf.Plugins.FileDataSource(dataDir + "Concat1.pdf"));
        opt.AddInput(new Aspose.Pdf.Plugins.FileDataSource(dataDir + "Concat2.pdf"));
        opt.AddOutput(new Aspose.Pdf.Plugins.FileDataSource(dataDir + "ConcatenatePdfFiles_out.pdf"));

        // Process the PDF merging
        merger.Process(opt);
    }
}

此外，从此版本开始添加了 ChatGPT 插件：

private static async void InvokeChatGptPlugin()
{
    using (var plugin = new Aspose.Pdf.Plugins.PdfChatGpt())
    {
        var options = new Aspose.Pdf.Plugins.PdfChatGptRequestOptions();
        options.AddOutput(new Aspose.Pdf.Plugins.FileDataSource("PdfChatGPT_output.pdf")); // Add the output file path.
        options.ApiKey = "Your API key."; // You need to provide the key to access the API.
        options.MaxTokens = 1000; // The maximum number of tokens to generate in the chat completion.

        // Add the request messages.
        options.Messages.Add(new Aspose.Pdf.Plugins.Message
        {
            Content = "You are annotation helpful assistant.",
            Role = Aspose.Pdf.Plugins.Role.System
        });
        options.Messages.Add(new Aspose.Pdf.Plugins.Message
        {
            Content = "What is the biggest pizza diameter ever made?",
            Role = Aspose.Pdf.Plugins.Role.User
        });

        // Process the request.
        var result = await plugin.ProcessAsync(options);

        var fileResultPath = result.ResultCollection[0].Data;

        // The ChatGPT API chat completion object.
        var chatCompletionObject = result.ResultCollection[1].Data as Aspose.Pdf.Plugins.ChatCompletion;
    }
}

Aspose.PDF 23.11 中的新功能

从此版本开始，可以从 PDF 文件中删除隐藏文本：

private static void RemoveHiddenText()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "HiddenText.pdf"))
    {
        // Use TextFragmentAbsorber with no parameters to get all text
        var textAbsorber = new Aspose.Pdf.Text.TextFragmentAbsorber();

        // This option can be used to prevent other text fragments from moving after hidden text replacement
        textAbsorber.TextReplaceOptions = new Aspose.Pdf.Text.TextReplaceOptions(Aspose.Pdf.Text.TextReplaceOptions.ReplaceAdjustment.None);

        document.Pages.Accept(textAbsorber);

        // Remove hidden text
        foreach (var fragment in textAbsorber.TextFragments)
        {
            if (fragment.TextState.Invisible)
            {
                fragment.Text = "";
            }
        }

        // Save PDF document
        document.Save(dataDir + "HiddenText_out.pdf");
    }
}

自 23.11 起，支持线程中断：

private static void InterruptExample()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    using (var monitor = new Aspose.Pdf.Multithreading.InterruptMonitor())
    {
        // An class that can produce long-drawn-out work
        RowSpanWorker worker = new RowSpanWorker(dataDir + "RowSpanWorker_out.pdf", monitor);

        var thread = new System.Threading.Thread(new System.Threading.ThreadStart(worker.Work));
        thread.Start();

        // The timeout should be less than the time required for full document save (without interruption)
        System.Threading.Thread.Sleep(500);

        // Interrupt the process
        monitor.Interrupt();

        // Wait for interruption...
        thread.Join();
    }
}

private class RowSpanWorker
{
    private readonly string outputPath;
    private readonly Aspose.Pdf.Multithreading.InterruptMonitor monitor;

    public RowSpanWorker(string outputPath, Aspose.Pdf.Multithreading.InterruptMonitor monitor)
    {
        this.outputPath = outputPath;
        this.monitor = monitor;
    }

    public void Work()
    {
        // This is some large text, used Lorem Ipsum in 10000 characters to cause suspension in processing
        string text = RunExamples.GetLoremIpsumString(10000);

        // Open PDF document
        using (var document = new Aspose.Pdf.Document())
        {
            Aspose.Pdf.Multithreading.InterruptMonitor.ThreadLocalInstance = this.monitor;
            var page = document.Pages.Add();

            var table = new Aspose.Pdf.Table
            {
                DefaultCellBorder = new Aspose.Pdf.BorderInfo(Aspose.Pdf.BorderSide.All, 0.1F)
            };

            var row0 = table.Rows.Add();

            // Add annotation cell that spans for two rows and contains annotation long-long text
            var cell00 = row0.Cells.Add(text);
            cell00.RowSpan = 2;
            cell00.IsWordWrapped = true;
            row0.Cells.Add("Ipsum Ipsum Ipsum Ipsum Ipsum Ipsum ");
            row0.Cells.Add("Dolor Dolor Dolor Dolor Dolor Dolor ");

            var row1 = table.Rows.Add();
            row1.Cells.Add("IpsumDolor Dolor Dolor Dolor Dolor ");
            row1.Cells.Add("DolorDolor Dolor Dolor Dolor Dolor ");

            page.Paragraphs.Add(table);

            try
            {
                // Save PDF document
                document.Save(this.outputPath);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }
    }
}

Aspose.PDF 23.10 中的新功能

当前更新提供了三种从标记 PDF 中删除标签的版本。

• 从 documentElement（根树元素）中删除某些节点元素：

private static void RemoveStructElement()
{
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "StructureElementsTree.pdf"))
    {
        // Access to root element(s)
        var structure = document.LogicalStructure;
        var documentElement = structure.Children[0];
        var structElement = documentElement.Children.Count > 1 ? documentElement.Children[1] as Aspose.Pdf.Structure.StructElement : null;

        if (documentElement.Children.Remove(structElement))
        {
            // Element removed. Save PDF document.
            document.Save(dataDir + "StructureElementsRemoved.pdf");
        }

        // You can also delete the structElement itself
        //if (structElement != null)
        //{
        //    structElement.Remove();
        //    document.Save(outputPdfPath);
        //}
    }
}

• 从文档中删除所有标记元素标签，但保留结构元素：

private static void RemoveMarkedElementsTags()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "TH.pdf"))
    {
        // Access to root element(s)
        var structure = document.LogicalStructure;
        var root = structure.Children[0];
        var queue = new Queue<Aspose.Pdf.Structure.Element>();
        queue.Enqueue(root);

        while (queue.TryDequeue(out var element))
        {
            foreach (var child in element.Children)
            {
                queue.Enqueue(child);
            }

            if (element is Aspose.Pdf.Structure.TextElement || element is Aspose.Pdf.Structure.FigureElement)
            {
                element.Remove();
            }
        }

        // Save PDF document
        document.Save(dataDir + "MarkedElementsTagsRemoved.pdf");
    }
}

• 完全删除标签：

private static void RemoveTags()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "TH.pdf"))
    {
        // Access to root element(s)
        var structure = document.LogicalStructure;
        var documentElement = structure.Children[0];
        documentElement.Remove();

        // Save PDF document
        document.Save(dataDir + "TagsRemoved.pdf");
    }
}

自 23.10 起，实现了一项新功能以测量字符高度。使用以下代码测量字符的高度。

private static void DisplayCharacterHeight()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "ExtractTextAll.pdf"))
    {
        // Create TextFragmentAbsorber to get information about state of document text
        var absorber = new Aspose.Pdf.Text.TextFragmentAbsorber();
        absorber.Visit(document.Pages[1]);

        // Get height of 'A' character being displayed with font of first text fragment
        var textState = absorber.TextFragments[1].TextState;
        var height = textState.MeasureHeight('A');
        Console.WriteLine("The height of 'A' character displayed with {0} font size of {1} is {2:N3}", textState.Font.FontName, textState.FontSize,height);
    }
}

请注意，测量基于文档中嵌入的字体。如果缺少任何维度的信息，此方法将返回 0。

此外，此版本提供了使用签名 HASH 签署 PDF 的功能：

private static void SignPdfUsingSignedHash(string certP12, string pfxPassword)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Instantiate PdfFileSignature object
    using (var sign = new Aspose.Pdf.Facades.PdfFileSignature())
    {
        // Bind PDF document
        sign.BindPdf(dataDir + "input.pdf");
        var pkcs7 = new Aspose.Pdf.Forms.PKCS7(certP12, pfxPassword);

        // Create a delegate to external sign
        pkcs7.CustomSignHash = delegate (byte[] signableHash, Aspose.Pdf.DigestHashAlgorithm digestHashAlgorithm)
        {
            X509Certificate2 signerCert = new X509Certificate2(certP12, pfxPassword, X509KeyStorageFlags.Exportable);
            RSACryptoServiceProvider rsaCSP = new RSACryptoServiceProvider();
            var xmlString = signerCert.PrivateKey.ToXmlString(true);    //not supported on core 2.0
            rsaCSP.FromXmlString(xmlString);                            //not supported on core 2.0

            byte[] signedData = rsaCSP.SignHash(signableHash, CryptoConfig.MapNameToOID("SHA1"));
            return signedData;
        };

        // Sign PDF file
        sign.Sign(1, "reason", "cont", "loc", false, new System.Drawing.Rectangle(0, 0, 500, 500), pkcs7);

        // Save PDF document
        sign.Save(dataDir + "SignWithCertificate_out.pdf");
    }

    // Verify
    using (var sign = new Aspose.Pdf.Facades.PdfFileSignature())
    {
        // Bind PDF document
        sign.BindPdf(dataDir + "SignWithCertificate_out.pdf");

        if (!sign.VerifySignature("Signature1"))
        {
            throw new Exception("Not verified");
        }
    }
}

另一个新功能是打印对话框预设页面缩放：

private static void SetPrintScaling()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Printing();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        document.Pages.Add();

        // Disable print scaling
        document.PrintScaling = PrintScaling.None;

        // Save PDF document
        document.Save(dataDir + "SetPrintScaling_out.pdf");
    }
}

Aspose.PDF 23.9 中的新功能

自 23.9 起，支持从可填写字段中删除子注释。

private static void RemoveChildAnnotationFromFillableField()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "FieldWithChildAnnots.pdf"))
    {
        // Get field with child annotations
        var field = (Aspose.Pdf.Forms.Field)document.Form["1 Vehicle Identification Number"];
        // Get first child annotation
        var annotation = field[1];
        // Remove the annotation
        document.Pages[annotation.PageIndex].Annotations.Remove(annotation);

        // Save PDF document
        document.Save(dataDir + "RemoveChildAnnotation_out.pdf");
    }
}

Aspose.PDF 23.8 中的新功能

自 23.8 起，支持添加增量更新检测。

在 PDF 文档中添加了检测增量更新的功能。此功能返回 ’true’ 如果文档是以增量更新保存的；否则返回 ‘false’。

private static bool HasIncrementalUpdate()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PdfWithIncrementalUpdate.pdf"))
    {
        // New method
        bool hasIncrementalUpdate = document.HasIncrementalUpdate();

        Console.WriteLine("Document {0} incremental update check returns: {1}", document.FileName, hasIncrementalUpdate);
        return hasIncrementalUpdate;
    }
}

此外，23.8 支持处理嵌套复选框字段的方式。许多可填写的 PDF 表单具有作为单选组的复选框字段：

• 创建多值复选框字段：

private static void CreateMultivalueCheckboxField()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();

        var checkbox = new Aspose.Pdf.Forms.CheckboxField(page, new Aspose.Pdf.Rectangle(50, 50, 70, 70));

        // Set the first checkbox group option value
        checkbox.ExportValue = "option 1";

        // Add new option right under existing ones
        checkbox.AddOption("option 2");

        // Add new option at the given rectangle
        checkbox.AddOption("option 3", new Aspose.Pdf.Rectangle(100, 100, 120, 120));

        document.Form.Add(checkbox);

        // Select the added checkbox
        checkbox.Value = "option 2";

        // Save PDF document
        document.Save(dataDir + "MultivalueCheckboxField.pdf");
    }
}

• 获取和设置多值复选框的值：

private static void GetAndSetValueOfMultivalueCheckboxField()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "MultivalueCheckboxField.pdf"))
    {
        var form = document.Form;
        var checkbox = form.Fields[0] as Aspose.Pdf.Forms.CheckboxField;

        // Allowed values may be retrieved from the AllowedStates collection
        // Set the checkbox value using Value property
        checkbox.Value = checkbox.AllowedStates[0];
        var checkboxValue = checkbox.Value; // the previously set value, e.g. "option 1"

        // The value should be any element of AllowedStates
        checkbox.Value = "option 2";
        checkboxValue = checkbox.Value; // option 2

        // Uncheck boxes by either setting Value to "Off" or setting Checked to false
        checkbox.Value = "Off";
        // or, alternately:
        // checkbox.Checked = false;
        checkboxValue = checkbox.Value; // Off
    }
}

Aspose.PDF 23.7 中的新功能

从 Aspose.PDF 23.7 开始，支持添加形状提取：

private static void CopyShape()
{
    // The path to the document directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Graphs();

    // Open PDF document
    using (var sourceDocument = new Aspose.Pdf.Document(dataDir + "test.pdf"))
    {
        // Create PDF document
        using (var destDocument = new Aspose.Pdf.Document())
        {
            // Absorb vector graphics from the source document
            var graphicAbsorber = new Aspose.Pdf.Vector.GraphicsAbsorber();
            graphicAbsorber.Visit(sourceDocument.Pages[1]);

            // Copy the graphics into the destination document specified page and area
            var area = new Aspose.Pdf.Rectangle(90, 250, 300, 400);
            destDocument.Pages[1].AddGraphics(graphicAbsorber.Elements, area);

            // Save PDF document
            destDocument.Save(dataDir + "CopyShape_out.pdf");
        }
    }
}

还支持在添加文本时检测溢出：

private static void FitTextIntoRectangle()
{
    // The path to the document directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document()) 
    {
        // Generate text to add: "Lorem Ipsum" text of 1000 characters
        var paragraphContent = RunExamples.GetLoremIpsumString(1000);
        // Create a text fragment with the desired text
        var fragment = new Aspose.Pdf.Text.TextFragment(paragraphContent);
        // Declare the rectangle to fit text into
        var rectangle = new Aspose.Pdf.Rectangle(100, 600, 500, 700, false);
        
        // Check whether the text fits into the rectangle
        var isFitRectangle = fragment.TextState.IsFitRectangle(paragraphContent, rectangle);

        // Iteratively decrease font size until text fits the rectangle
        while (!isFitRectangle)
        {
            fragment.TextState.FontSize -= 0.5f;
            isFitRectangle = fragment.TextState.IsFitRectangle(paragraphContent, rectangle);
        }

        // Create a paragraph from the text fragment in the specified rectangle. Now you may be sure it fits.
        var paragraph = new Aspose.Pdf.Text.TextParagraph();
        paragraph.VerticalAlignment = Aspose.Pdf.VerticalAlignment.Top;
        paragraph.FormattingOptions.WrapMode = Aspose.Pdf.Text.TextFormattingOptions.WordWrapMode.ByWords;
        paragraph.Rectangle = rectangle;
        paragraph.AppendLine(fragment);

        // Create a text builder to place the paragraph on the document page
        var builder = new Aspose.Pdf.Text.TextBuilder(document.Pages.Add());
        builder.AppendParagraph(paragraph);

        // Save PDF document
        document.Save(dataDir + "FitTextIntoRectangle_out.pdf");
    }
}

Aspose.PDF 23.6 中的新功能

从 Aspose.PDF 23.6 开始，支持添加以下插件：

• Aspose PdfConverter Html 到 PDF
• Aspose PdfOrganizer 调整大小 API
• Aspose PdfOrganizer 压缩 API

更新 Aspose.PdfForm

• 添加功能 ‘将文档中的字段值导出到 CSV 文件’
• 添加为单个字段设置属性的能力

还支持设置 HTML、Epub 页面的标题：

private static void SetHtmlTitle()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PDFToHTML.pdf"))
    {
        var options = new Aspose.Pdf.HtmlSaveOptions
        {
            ExplicitListOfSavedPages = new[] { 1 },
            SplitIntoPages = false,
            FixedLayout = true,
            CompressSvgGraphicsIfAny = false,
            SaveTransparentTexts = true,
            SaveShadowedTextsAsTransparentTexts = true,
            FontSavingMode = Aspose.Pdf.HtmlSaveOptions.FontSavingModes.AlwaysSaveAsWOFF,
            RasterImagesSavingMode = Aspose.Pdf.HtmlSaveOptions.RasterImagesSavingModes.AsEmbeddedPartsOfPngPageBackground,
            PartsEmbeddingMode = Aspose.Pdf.HtmlSaveOptions.PartsEmbeddingModes.EmbedAllIntoHtml,
            // New property
            Title = "Title for page"
        };

        // Save HTML document
        document.Save(dataDir + "SetHtmlTitle_out.html", options);
    }
}

Aspose.PDF 23.5 中的新功能

自 23.5 起，支持添加 RedactionAnnotation FontSize 选项。使用以下代码片段解决此任务：

private static void AddRedactionAnnotationFontSize() 
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Annotations();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf")) 
    {
        // Create RedactionAnnotation instance for specific page region
        var annot = new Aspose.Pdf.Annotations.RedactionAnnotation(document.Pages[1],
            new Aspose.Pdf.Rectangle(367, 756.919982910156, 420, 823.919982910156));
        annot.FillColor = Aspose.Pdf.Color.Black;

        annot.BorderColor = Aspose.Pdf.Color.Yellow;
        annot.Color = Aspose.Pdf.Color.Blue;
        // Text to be printed on redact annotation
        annot.OverlayText = "(Unknown)";
        annot.TextAlignment = Aspose.Pdf.HorizontalAlignment.Center;
        // Repat Overlay text over redact Annotation
        annot.Repeat = false;

        // New property
        annot.FontSize = 20;

        // Add annotation to annotations collection of first page
        document.Pages[1].Annotations.Add(annot);
        // Flattens annotation and redacts page contents (i.e. removes text and image under redacted annotation)
        annot.Redact();
        // Save PDF document
        document.Save(dataDir + "AddRedactionAnnotationFontSize_out.pdf");
    }
}

Aspose.PDF 23.4 中的新功能

Aspose.PDF 宣布发布 .NET 7 SDK。

Aspose.PDF 23.3.1 中的新功能

从 Aspose.PDF 23.3 开始，支持添加以下插件：

• Aspose.PdfForm
• Aspose.PdfConverter PDF 到 HTML
• Aspose.PdfConverter PDF 到 XLSX
• Aspose.PdfOrganizer 旋转
• Aspose.PdfExtrator 用于图像

Aspose.PDF 23.3 中的新功能

版本 23.3 引入了在页面插入时保持图像比例和分辨率的支持。可以使用两种方法解决此问题：

private static void InsertImageWithNativeResolutionAsTable()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();

        var table = new Aspose.Pdf.Table
        {
            ColumnWidths = "600"
        };

        for (var j = 0; j < 2; j++)
        {
            var row = table.Rows.Add();
            var cell = row.Cells.Add();
            cell.Paragraphs.Add(new Aspose.Pdf.Image()
            {
                IsApplyResolution = true,
                File = dataDir + "Image1.jpg"
            });
        }

        page.Paragraphs.Add(table);

        // Save PDF document
        document.Save(dataDir + "ImageWithNativeResolutionAsTable_out.pdf");
    }
}

第二种方法：

private static void InsertImageWithNativeResolutionAsParagraph()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();

        for (var j = 0; j < 2; j++)
        {
            page.Paragraphs.Add(new Aspose.Pdf.Image()
            {
                IsApplyResolution = true,
                File = dataDir + "Image1.jpg"
            });
        }

        // Save PDF document
        document.Save(dataDir + "ImageWithNativeResolutionAsParagraph_out.pdf");
    }
}

图像将以缩放大小和原生分辨率放置。您可以结合使用 FixedWidth 或 FixedHeight 属性与 IsApplyResolution。

Aspose.PDF 23.1.1 中的新功能

从 Aspose.PDF 23.1.1 开始，支持添加以下插件：

• Aspose.PdfOrganizer 插件
• Aspose.PdfExtractor 插件

Aspose.PDF 23.1 中的新功能

自 23.1 版本起，支持创建 PrinterMark 注释。

打印机标记是添加到页面的图形符号或文本，以帮助生产人员识别多版作业的组件，并在生产过程中保持一致的输出。印刷行业常用的示例包括：

• 对齐版的注册目标
• 测量颜色和墨水密度的灰色渐变和色条
• 显示输出介质应修剪位置的切割标记

我们将展示带有测量颜色和墨水密度的色条的选项示例。基本抽象类 PrinterMarkAnnotation 及其子类 ColorBarAnnotation - 已实现这些条纹。让我们检查示例：

private static void AddPrinterMarkAnnotation()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Annotations();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        var page = document.Pages.Add();
        page.TrimBox = new Aspose.Pdf.Rectangle(20, 20, 580, 820);

        var rectBlack = new Aspose.Pdf.Rectangle(100, 300, 300, 320);
        var rectCyan = new Aspose.Pdf.Rectangle(200, 600, 260, 690);
        var rectMagenta = new Aspose.Pdf.Rectangle(10, 650, 140, 670);

        var colorBarBlack = new Aspose.Pdf.Annotations.ColorBarAnnotation(page, rectBlack);
        var colorBarCyan = new Aspose.Pdf.Annotations.ColorBarAnnotation(page, rectCyan,
            Aspose.Pdf.Annotations.ColorsOfCMYK.Cyan);
        var colorBarMagenta = new Aspose.Pdf.Annotations.ColorBarAnnotation(page, rectMagenta);
        colorBarMagenta.ColorOfCMYK = Aspose.Pdf.Annotations.ColorsOfCMYK.Magenta;
        var colorBarYellow = new Aspose.Pdf.Annotations.ColorBarAnnotation(page,
            new Aspose.Pdf.Rectangle(400, 250, 450, 700), Aspose.Pdf.Annotations.ColorsOfCMYK.Yellow);

        page.Annotations.Add(colorBarBlack);
        page.Annotations.Add(colorBarCyan);
        page.Annotations.Add(colorBarMagenta);
        page.Annotations.Add(colorBarYellow);

        // Save PDF document
        document.Save(dataDir + "PrinterMarkAnnotation_out.pdf");
    }
}

还支持矢量图像提取。尝试使用以下代码检测和提取矢量图形：

private static void SavePdfVectorGraphicToSvg()
{
    // The path to the document directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Graphs();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "test.pdf"))
    {
        // Attempt to save the vector graphics into a specified SVG file
        document.Pages[1].TrySaveVectorGraphics(dataDir + "PdfVectorGraphicToSvg.svg");
    }
}

Aspose.PDF 22.12 中的新功能

从此版本开始，支持将 PDF 转换为 DICOM 图像。

private static void PdfToDicom()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PagesToImages.pdf"))
    {
        var dicom = new Aspose.Pdf.Devices.DicomDevice();
        FileStream outStream = new FileStream(dataDir + "PdfToDicom_out.dcm", FileMode.Create, FileAccess.ReadWrite);
        dicom.Process(document.Pages[1], outStream);
    }
}

Aspose.PDF 22.09 中的新功能

自 22.09 起，支持添加属性以修改签名中的主题标题顺序 (E=, CN=, O=, OU=)。

private static void SignPdfWithModifiedOrderOfSubjectRubrics(string pfxFilePath, string password)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Instantiate PdfFileSignature object
    using (var fileSign = new Aspose.Pdf.Facades.PdfFileSignature())
    {
        // Bind PDF document
        fileSign.BindPdf(dataDir + "DigitallySign.pdf");

        var rect = new System.Drawing.Rectangle(100, 100, 400, 100);
        var signature = new Aspose.Pdf.Forms.PKCS7Detached(pfxFilePath, password);

        // Set signature custom appearance
        signature.CustomAppearance = new Aspose.Pdf.Forms.SignatureCustomAppearance()
        {
            UseDigitalSubjectFormat = true,
            DigitalSubjectFormat = new Aspose.Pdf.Forms.SubjectNameElements[] { Aspose.Pdf.Forms.SubjectNameElements.CN, Aspose.Pdf.Forms.SubjectNameElements.O }
            //or
            //DigitalSubjectFormat = new Aspose.Pdf.Forms.SubjectNameElements[] { Aspose.Pdf.Forms.SubjectNameElements.OU, Aspose.Pdf.Forms.SubjectNameElements.S, Aspose.Pdf.Forms.SubjectNameElements.C }
        };

        // Sign PDF file
        fileSign.Sign(1, true, rect, signature);
        // Save PDF document
        fileSign.Save(dataDir + "SignPdfWithModifiedOrderOfSubjectRubrics_out.pdf");
    }
}

Aspose.PDF 22.6 中的新功能

自 22.5 起，支持从 PDF 中提取下标和上标文本。

如果 PDF 文档包含下标和上标文本，例如 H2O，则从 PDF 中提取文本时也必须提取其格式信息（在提取的纯文本中）。 如果 PDF 中包含斜体文本，则也必须包含在提取的内容中。

private static void ExtractTextSuperscript()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "TextWithSubscriptsSuperscripts.pdf"))
    {
        // Use TextFragmentAbsorber with no parameters to get all text
        var absorber = new Aspose.Pdf.Text.TextFragmentAbsorber();
        absorber.Visit(document.Pages[1]);

        // Iterate through text fragments to find superscript text
        foreach (var textFragment in absorber.TextFragments) 
        {
            if (textFragment.TextState.Superscript)
            {
                Console.WriteLine(String.Format("Text {0} at {1} is superscript!", textFragment.Text, textFragment.Position));
            }
        }
    }
}

Aspose.PDF 22.4 中的新功能

此版本包括 Aspose.PDF for .NET 的信息：

• PDF 到 ODS：识别下标和上标中的文本；

示例

private static void ConvertPdfToOds()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "input.pdf"))
    {
        // Instantiate ExcelSaveOptions object
        var saveOptions = new Aspose.Pdf.ExcelSaveOptions
        {
            // Specify the desired table file format
            Format = Aspose.Pdf.ExcelSaveOptions.ExcelFormat.ODS
        };

        // Save the file in ODS format
        document.Save(dataDir + "PDFToODS_out.ods", saveOptions);
    }
}

• PDF 到 XMLSpreadSheet2003：识别下标和上标中的文本；

• PDF 到 Excel：识别下标和上标中的文本；

• 保存文档时删除 UR 签名；

• 保存文档时删除 MarkInfo 中的 Suspects 标志；

• 保存文档时删除信息。

Aspose.PDF 22.3 中的新功能

此版本包括以下更新：

• 支持 AFRelationship；

• PDF 头部验证；

• 保存文档时删除 adbe.x509.rsa_sha1 子过滤器；

• 将字段格式化为数字和日期格式；

• 禁止在 FDF 2.0 中使用 RC4 加密。

Aspose.PDF 22.2 中的新功能

从 22.2 版本开始，可以使用 PdfFileSignature 签署文档，并能够将哈希从 SHA1 更改为 SHA256。

private static void SignPdfWithSha256(string pfxFilePath, string password)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Instantiate PdfFileSignature object
    using (var fileSign = new Aspose.Pdf.Facades.PdfFileSignature())
    {
        // Bind PDF document
        fileSign.BindPdf(dataDir + "DigitallySign.pdf");

        var rect = new System.Drawing.Rectangle(300, 100, 1, 1);
        var signature = new Aspose.Pdf.Forms.PKCS7(pfxFilePath, password)
        {
            UseLtv = true,
            TimestampSettings = new Aspose.Pdf.TimestampSettings("http://freetsa.org/tsr", string.Empty, Aspose.Pdf.DigestHashAlgorithm.Sha256)
        };

        // Sign PDF file
        fileSign.Sign(1, false, rect, signature);
        // Save PDF document
        fileSign.Save(dataDir + "SignPdfWithSha256_out.pdf");
    }
}

Aspose.PDF 22.1 中的新功能

现在，Aspose.PDF for .NET 支持从最流行的文档格式之一，即可移植文档格式 (PDF) 版本 2.0 加载文档。

Aspose.PDF 21.11 中的新功能

允许密码中使用非拉丁字符

private static void EncriptPdfNonlatinPassCharacters()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    using (var fileSecurity = new Aspose.Pdf.Facades.PdfFileSecurity())
    {
        // Bind PDF document
        fileSecurity.BindPdf(dataDir + "input.pdf");
        // Encrypt file using 256-bit encryption
        bool isSuccessful = fileSecurity.EncryptFile("æøå", "æøå", Aspose.Pdf.Facades.DocumentPrivilege.Print,
            Aspose.Pdf.Facades.KeySize.x256, Aspose.Pdf.Facades.Algorithm.AES);
        Console.WriteLine(isSuccessful);
        // Save PDF document
        fileSecurity.Save(dataDir + "PdfNonlatinPassEncrypted_out.pdf");
    }
}

Aspose.PDF 21.10 中的新功能

如何检测隐藏文本？

请使用 TextState.Invisible 获取有关文本不可见性的信息，超出渲染模式设置。

我们使用以下代码进行测试：

private static void DisplayTextInvisibility()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PdfWithHiddenText.pdf"))
    {
        Console.WriteLine(document.FileName);

        // Use TextFragmentAbsorber with no parameters to get all text
        var absorber = new Aspose.Pdf.Text.TextFragmentAbsorber();
        absorber.Visit(document.Pages[1]);
        var textFragmentCollection = absorber.TextFragments;

        // Iterate through text fragments to find hidden text
        for (int i = 1; i <= textFragmentCollection.Count; i++)
        {
            var fragment = textFragmentCollection[i];
            Console.WriteLine("Fragment {0} at {1}", i, fragment.Rectangle.ToString());
            Console.WriteLine("Text: {0}", fragment.Text);
            Console.WriteLine("RenderingMode: {0}", fragment.TextState.RenderingMode.ToString());
            Console.WriteLine("Invisibility: {0}", fragment.TextState.Invisible);
            Console.WriteLine("---");
        }
    }
}

如何获取 PDF 文档中层的数量信息？

private static void GetPdfLayers()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Layers();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PdfWithLayers.pdf"))
    {
        // Get layers from the first page
        var layers = document.Pages[1].Layers;
        // Save each layer to the output path
        foreach (var layer in layers)
        {
            Console.WriteLine("Document {0} contains a layer named: {1} ", document.FileName, layer.Name);
        }
    }
}

Aspose.PDF 21.9 中的新功能

自 21.9 起，支持自定义签名外观的背景颜色和签名区域标签的字体颜色。

private static void SignPdfWithCustomColorsInAppearance(string pfxFilePath, string password)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Instantiate PdfFileSignature object
    using (var pdfFileSignature = new Aspose.Pdf.Facades.PdfFileSignature())
    {
        // Bind PDF document
        pdfFileSignature.BindPdf(dataDir + "DigitallySign.pdf");
        var rect = new System.Drawing.Rectangle(310, 45, 200, 50);
        // Create PKCS#7 object for sign
        var pkcs = new Aspose.Pdf.Forms.PKCS7(pfxFilePath, password);

        // Set signature custom appearance
        pkcs.CustomAppearance = new Aspose.Pdf.Forms.SignatureCustomAppearance()
        {
            // Set colors
            ForegroundColor = Aspose.Pdf.Color.DarkGreen,
            BackgroundColor = Aspose.Pdf.Color.LightSeaGreen,
        };
        // Sign PDF file
        pdfFileSignature.Sign(1, true, rect, pkcs);
        // Save PDF document
        pdfFileSignature.Save(dataDir + "SignPdfWithCustomColorsInAppearance_out.pdf");
    }
}

Aspose.PDF 21.8 中的新功能

如何更改数字签名中的文本颜色？

在 21.8 版本中，ForegroundColor 属性允许更改数字签名中的文本颜色。

private static void SignPdfWithForegroundColorInAppearance(string pfxFilePath, string password)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    // Instantiate PdfFileSignature object
    using (var pdfSign = new Aspose.Pdf.Facades.PdfFileSignature())
    {
        // Bind PDF document
        pdfSign.BindPdf(dataDir + "DigitallySign.pdf");
        var rect = new System.Drawing.Rectangle(310, 45, 200, 50);
        // Create PKCS#7 object for sign
        var pkcs = new Aspose.Pdf.Forms.PKCS7(pfxFilePath, password);

        // Set signature custom appearance
        pkcs.CustomAppearance = new Aspose.Pdf.Forms.SignatureCustomAppearance()
        {
            // Set text color
            ForegroundColor = Aspose.Pdf.Color.Green
        };
        // Sign PDF file
        pdfSign.Sign(1, true, rect, pkcs);
        // Save PDF document
        pdfSign.Save(dataDir + "SignPdfWithForegroundInAppearance_out.pdf");
    }
}

Aspose.PDF 21.7 中的新功能

基于 XML 和 XLS 的 PDF 创建

要添加 XSL 参数，我们需要创建自己的 XsltArgumentList 并将其设置为 XslFoLoadOptions 中的属性。以下代码片段展示了如何使用此类与上述示例文件。

private static void ConvertXslfoToPdfWithArgumentList()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // Create convert options
    var options = new Aspose.Pdf.XslFoLoadOptions(dataDir + "XSLFOToPdfInput.xslt");

    // Example of using XsltArgumentList
    options.XsltArgumentList = new XsltArgumentList();
    options.XsltArgumentList.AddParam("isBoldName", "", "yes");

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "XSLFOToPdfInput.xml", options))
    {
        // Save PDF document
        document.Save(dataDir + "XslfoToPdfWithArgumentList_out.pdf");
    }
}

Aspose.PDF 21.6 中的新功能

使用 Aspose.PDF for .NET，您可以使用 ImagePlacementAbsorber 从文档中隐藏图像：

private static void HideImageInPdf()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "ImagePlacement.pdf"))
    {
        // Create ImagePlacementAbsorber instance
        var absorber = new Aspose.Pdf.ImagePlacementAbsorber();
        // Load the images of the first page
        document.Pages[1].Accept(absorber);

        // Iterate through each image placement on the first page
        foreach (var imagePlacement in absorber.ImagePlacements)
        {
            // Hide image
            imagePlacement.Hide();
        }

        // Save PDF document
        document.Save(dataDir + "HideImageInPdf_out.pdf");
    }
}

Aspose.PDF 21.5 中的新功能

如何从 PDF 的描述/资源中提取字体全名？

您可以通过 Font 类的 BaseFont 属性获取带前缀的完整字体。

private static void DisplayFontFullNames()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "BreakfastMenu.pdf"))
    {
        // Get document fonts
        var fonts = document.FontUtilities.GetAllFonts();

        // Iterate through the fonts
        foreach (var font in fonts)
        {
            // Show font names
            Console.WriteLine($"font name : {font.FontName} BaseFont name : {font.BaseFont}");
        }
    }
}

Aspose.PDF 21.4 中的新功能

添加合并图像的 API

Aspose.PDF 21.4 允许您合并图像。请遵循以下代码片段：

private static void MergeAsJpeg()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    List<Stream> inputImagesStreams = new List<Stream>();
    using (FileStream firstImageStream = new FileStream(dataDir + "aspose.jpg", FileMode.Open))
    {
        inputImagesStreams.Add(firstImageStream);
        using (FileStream secondImageStream = new FileStream(dataDir + "aspose-logo.jpg", FileMode.Open))
        {
            inputImagesStreams.Add(secondImageStream);

            // Invoke PdfConverter.MergeImages to perform merge
            using (Stream inputStream = Aspose.Pdf.Facades.PdfConverter.MergeImages(inputImagesStreams,
                  Aspose.Pdf.Drawing.ImageFormat.Jpeg, Aspose.Pdf.Facades.ImageMergeMode.Vertical, 1, 1))
            {
                using (FileStream outputStream = new FileStream(dataDir + "Merge_out.jpg", FileMode.Create))
                {
                    byte[] buffer = new byte[32768];
                    int read;
                    while ((read = inputStream.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        outputStream.Write(buffer, 0, read);
                    }
                }
            }
        }
    }
}

您还可以将图像合并为 Tiff 格式：

private static void MergeAsTiff()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    List<Stream> inputImagesStreams = new List<Stream>();
    using (FileStream firstImageStream = new FileStream(dataDir + "aspose.jpg", FileMode.Open))
    {
        inputImagesStreams.Add(firstImageStream);
        using (FileStream secondImageStream = new FileStream(dataDir + "aspose-logo.jpg", FileMode.Open))
        {
            inputImagesStreams.Add(secondImageStream);

            // Invoke PdfConverter.MergeImagesAsTiff to perform merge
            using (Stream inputStream = Aspose.Pdf.Facades.PdfConverter.MergeImagesAsTiff(inputImagesStreams))
            {
                using (FileStream outputStream = new FileStream(dataDir + "Merge_out.tiff", FileMode.Create))
                {
                    byte[] buffer = new byte[32768];
                    int read;
                    while ((read = inputStream.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        outputStream.Write(buffer, 0, read);
                    }
                }
            }
        }
    }
}

Aspose.PDF 21.3 中的新功能

公开检测 Azure 信息保护的属性

使用以下代码片段，您应该能够访问受 Azure 信息保护保护的 PDF 文件的加密有效负载：

private static void AzureInformationProtection()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Attachments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetAlltheAttachments.pdf"))
    {
        if (document.EmbeddedFiles[1].AFRelationship == Aspose.Pdf.AFRelationship.EncryptedPayload)
        {
            if (document.EmbeddedFiles[1].EncryptedPayload != null)
            {
                // document.EmbeddedFiles[1].EncryptedPayload.Type == "EncryptedPayload"
                // document.EmbeddedFiles[1].EncryptedPayload.Subtype == "MicrosoftIRMServices"
                // document.EmbeddedFiles[1].EncryptedPayload.Version == "2"
            }
        }
    }
}

Aspose.PDF 21.1 中的新功能

添加检索 TextFragment 背景颜色的支持

在此版本的 Aspose.PDF 中，检索背景颜色的功能变得可用。您需要在 TextFragmentAbsorber 对象的选项中指定 searchOptions.SearchForTextRelatedGraphics = true;。

请考虑以下代码：

private static void DisplayPdfTextBackgroundColor()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PdfWithTextBackgroundColor.pdf"))
    {
        // Use TextFragmentAbsorber with no parameters to get all text
        var textFragmentAbsorber = new Aspose.Pdf.Text.TextFragmentAbsorber();

        var searchOptions = new Aspose.Pdf.Text.TextSearchOptions(false);
        // Setting this option into the 'true' is necessary 
        searchOptions.SearchForTextRelatedGraphics = true;
        textFragmentAbsorber.TextSearchOptions = searchOptions;

        // Accept the absorber for all the pages
        document.Pages.Accept(textFragmentAbsorber);
        
        // Loop through the fragments
        foreach (var textFragment in textFragmentAbsorber.TextFragments)
        {
            Console.WriteLine("Text: '{0}'", textFragment.Text);
            Console.WriteLine("BackgroundColor: '{0}'", textFragment.TextState.BackgroundColor);
            Console.WriteLine("ForegroundColor: '{0}'", textFragment.TextState.ForegroundColor);
            Console.WriteLine("Segment BackgroundColor: '{0}'", textFragment.Segments[1].TextState.BackgroundColor);
        }
    }
}

转换为 HTML 后，字体完全嵌入输出中

此外，在 Aspose.PDF 21.1 中，将 PDF 转换为 HTML 后，输出 HTML 文档中可用嵌入字体。通过新的布尔保存选项 HtmlSaveParameter.SaveFullFont 实现。

以下是代码片段：

private static void PdfToHtmlWithFullFont()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PDFToHTML.pdf"))
    {
        // Instantiate HTML SaveOptions object
        var options = new Aspose.Pdf.HtmlSaveOptions
        {
            RasterImagesSavingMode = Aspose.Pdf.HtmlSaveOptions.RasterImagesSavingModes.AsEmbeddedPartsOfPngPageBackground,
            PartsEmbeddingMode = Aspose.Pdf.HtmlSaveOptions.PartsEmbeddingModes.EmbedAllIntoHtml,
            LettersPositioningMethod = Aspose.Pdf.HtmlSaveOptions.LettersPositioningMethods.UseEmUnitsAndCompensationOfRoundingErrorsInCss,
            FontSavingMode = Aspose.Pdf.HtmlSaveOptions.FontSavingModes.AlwaysSaveAsTTF,
            SaveTransparentTexts = true,
            // New option
            SaveFullFont = true
        };
        // Save HTML document
        document.Save(dataDir + "PdfToHtmlWithFullFont_out.html", options);
    }
}