Set XMP Metadata of an existing PDF

In order to set XMP metadata in a PDF file, you need to create PdfXmpMetadata object and bind the PDF file using BindPdf method. You can use Add method of the PdfXmpMetadata class to add different properties. Finally, call the Save method of the PdfXmpMetadata class. The following code snippet shows you how to add XMP metadata in a PDF file.

.NET Core 3.1

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

    // Create PdfXmpMetadata object
    using (var xmpMetaData = new Aspose.Pdf.Facades.PdfXmpMetadata())
    {
        // Bind PDF document
        xmpMetaData.BindPdf(dataDir + "SetXMPMetadata.pdf");

        // Add create date
        xmpMetaData.Add(Aspose.Pdf.Facades.DefaultMetadataProperties.CreateDate, DateTime.Now.ToString());

        // Change meta data date
        xmpMetaData[Aspose.Pdf.Facades.DefaultMetadataProperties.MetadataDate] = DateTime.Now.ToString();

        // Add creator tool
        xmpMetaData.Add(Aspose.Pdf.Facades.DefaultMetadataProperties.CreatorTool, "Creator tool name");

        // Remove modify date
        xmpMetaData.Remove(Aspose.Pdf.Facades.DefaultMetadataProperties.ModifyDate);

        // Add user defined property
        // Step #1: register namespace prefix and URI
        xmpMetaData.RegisterNamespaceURI("customNamespace", "http:// Www.customNameSpaces.com/ns/");

        // Step #2: add user property with the prefix
        xmpMetaData.Add("customNamespace:UserPropertyName", "UserPropertyValue");

        // Change user defined property
        xmpMetaData["customNamespace:UserPropertyName"] = "UserPropertyValue2";

        // Save PDF document
        xmpMetaData.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 AddXmpMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_WorkingDocuments();

    // Create PdfXmpMetadata object
    using var xmpMetaData = new Aspose.Pdf.Facades.PdfXmpMetadata();

    // Bind PDF document
    xmpMetaData.BindPdf(dataDir + "SetXMPMetadata.pdf");

    // Add create date
    xmpMetaData.Add(Aspose.Pdf.Facades.DefaultMetadataProperties.CreateDate, DateTime.Now.ToString());

    // Change meta data date
    xmpMetaData[Aspose.Pdf.Facades.DefaultMetadataProperties.MetadataDate] = DateTime.Now.ToString();

    // Add creator tool
    xmpMetaData.Add(Aspose.Pdf.Facades.DefaultMetadataProperties.CreatorTool, "Creator tool name");

    // Remove modify date
    xmpMetaData.Remove(Aspose.Pdf.Facades.DefaultMetadataProperties.ModifyDate);

    // Add user defined property
    // Step #1: register namespace prefix and URI
    xmpMetaData.RegisterNamespaceURI("customNamespace", "http:// Www.customNameSpaces.com/ns/");

    // Step #2: add user property with the prefix
    xmpMetaData.Add("customNamespace:UserPropertyName", "UserPropertyValue");

    // Change user defined property
    xmpMetaData["customNamespace:UserPropertyName"] = "UserPropertyValue2";

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