在 C# 中处理 PDF 文件元数据

以下代码片段也适用于 Aspose.PDF.Drawing 库。

获取 PDF 文件信息

为了获取 PDF 文件的特定信息，您首先需要使用 Document 对象的 Info 属性获取 DocumentInfo 对象。一旦检索到 DocumentInfo 对象，您可以获取各个属性的值。以下代码片段向您展示如何获取 PDF 文件信息。

.NET Core 3.1

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetFileInfo.pdf"))
    {
        // Get document information
        var docInfo = document.Info;

        // Display document information
        Console.WriteLine("Author: {0}", docInfo.Author);
        Console.WriteLine("Creation Date: {0}", docInfo.CreationDate);
        Console.WriteLine("Keywords: {0}", docInfo.Keywords);
        Console.WriteLine("Modify Date: {0}", docInfo.ModDate);
        Console.WriteLine("Subject: {0}", docInfo.Subject);
        Console.WriteLine("Title: {0}", docInfo.Title);
    }
}

.NET 8

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetFileInfo.pdf"))
    {
        // Get document information
        var docInfo = document.Info;
        // Display document information
        Console.WriteLine("Author: {0}", docInfo.Author);
        Console.WriteLine("Creation Date: {0}", docInfo.CreationDate);
        Console.WriteLine("Keywords: {0}", docInfo.Keywords);
        Console.WriteLine("Modify Date: {0}", docInfo.ModDate);
        Console.WriteLine("Subject: {0}", docInfo.Subject);
        Console.WriteLine("Title: {0}", docInfo.Title);
    }
}

设置 PDF 文件信息

Aspose.PDF for .NET 允许您为 PDF 设置特定的信息，例如作者、创建日期、主题和标题。要设置此信息：

1. 创建一个 DocumentInfo 对象。
2. 设置属性的值。
3. 使用 Document 类的 Save 方法保存更新后的文档。

以下代码片段向您展示如何设置 PDF 文件信息。

.NET Core 3.1

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetFileInfo.pdf"))
    {
        // Specify document information
        var docInfo = new Aspose.Pdf.DocumentInfo(document);

        docInfo.Author = "Aspose";
        docInfo.CreationDate = DateTime.Now;
        docInfo.Keywords = "Aspose.Pdf, DOM, API";
        docInfo.ModDate = DateTime.Now;
        docInfo.Subject = "PDF Information";
        docInfo.Title = "Setting PDF Document Information";
        docInfo.Producer = "Custom producer";
        docInfo.Creator = "Custom creator";

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

.NET 8

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetFileInfo.pdf"))
    {
        // Specify document information
        var docInfo = new Aspose.Pdf.DocumentInfo(document);

        docInfo.Author = "Aspose";
        docInfo.CreationDate = DateTime.Now;
        docInfo.Keywords = "Aspose.Pdf, DOM, API";
        docInfo.ModDate = DateTime.Now;
        docInfo.Subject = "PDF Information";
        docInfo.Title = "Setting PDF Document Information";
        docInfo.Producer = "Custom producer";
        docInfo.Creator = "Custom creator";

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

从 PDF 文件获取 XMP 元数据

Aspose.PDF 允许您访问 PDF 文件的 XMP 元数据。要获取 PDF 文件的元数据：

1. 创建一个 Document 对象并打开输入的 PDF 文件。
2. 使用 Metadata 属性获取文件的元数据。

以下代码片段向您展示如何从 PDF 文件获取元数据。

.NET Core 3.1

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetXMPMetadata.pdf"))
    {
        // Get and display properties
        Console.WriteLine($"Create Date: {document.Metadata["xmp:CreateDate"]}");
        Console.WriteLine($"Nickname: {document.Metadata["xmp:Nickname"]}");
        Console.WriteLine($"Custom Property: {document.Metadata["xmp:CustomProperty"]}");
    }
}

.NET 8

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetXMPMetadata.pdf"))
    {
        // Get and display properties
        Console.WriteLine($"Create Date: {document.Metadata["xmp:CreateDate"]}");
        Console.WriteLine($"Nickname: {document.Metadata["xmp:Nickname"]}");
        Console.WriteLine($"Custom Property: {document.Metadata["xmp:CustomProperty"]}");
    }
}

在 PDF 文件中设置 XMP 元数据

Aspose.PDF 允许您在 PDF 文件中设置元数据。要设置元数据：

1. 创建一个 Document 对象。
2. 使用 Metadata 属性设置元数据值。
3. 使用 Document 对象的 Save 方法保存更新后的文档。

以下代码片段向您展示如何在 PDF 文件中设置元数据。

.NET Core 3.1

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Set properties
        document.Metadata["xmp:CreateDate"] = DateTime.Now.ToString("o");
        document.Metadata["xmp:Nickname"] = "Nickname";
        document.Metadata["xmp:CustomProperty"] = "Custom Value";

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

.NET 8

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Set properties
        document.Metadata["xmp:CreateDate"] = DateTime.Now.ToString("o");
        document.Metadata["xmp:Nickname"] = "Nickname";
        document.Metadata["xmp:CustomProperty"] = "Custom Value";

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

插入带前缀的元数据

一些开发者需要创建一个带前缀的新元数据命名空间。以下代码片段展示了如何插入带前缀的元数据。

.NET Core 3.1

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Register a namespace URI for the 'xmp' prefix
        document.Metadata.RegisterNamespaceUri("xmp", "http://ns.adobe.com/xap/1.0/");

        // Set the metadata property using the registered prefix
        document.Metadata["xmp:ModifyDate"] = DateTime.Now.ToString("o"); // ISO 8601 format for datetime

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

.NET 8

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Register a namespace URI for the 'xmp' prefix
        document.Metadata.RegisterNamespaceUri("xmp", "http://ns.adobe.com/xap/1.0/");

        // Set the metadata property using the registered prefix
        document.Metadata["xmp:ModifyDate"] = DateTime.Now.ToString("o"); // ISO 8601 format for datetime

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