Add or remove attachments in PDF using C#

add-attachment.cs

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// Open document
Document pdfDocument = new Document("document.pdf");

// Setup new file to be added as attachment
FileSpecification fileSpecification = new FileSpecification("test.txt", "Sample text file");

// Add attachment to document's attachment collection
pdfDocument.EmbeddedFiles.Add(fileSpecification);

// Save new output
pdfDocument.Save("output.pdf");

get-attachment.cs

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// Open document
Document pdfDocument = new Document("document.pdf");

// Get particular embedded file
foreach(FileSpecification fileSpecification in pdfDocument.EmbeddedFiles)
{
    // Get the file properties
    Console.WriteLine("Name: {0}", fileSpecification.Name);
    Console.WriteLine("Description: {0}", fileSpecification.Description);
    Console.WriteLine("Mime Type: {0}", fileSpecification.MIMEType);

    // Check if parameter object contains the parameters
    if (fileSpecification.Params != null)
    {
        Console.WriteLine("CheckSum: {0}",
        fileSpecification.Params.CheckSum);
        Console.WriteLine("Creation Date: {0}",
        fileSpecification.Params.CreationDate);
        Console.WriteLine("Modification Date: {0}",
        fileSpecification.Params.ModDate);
        Console.WriteLine("Size: {0}", fileSpecification.Params.Size);
    }

    // Get the attachment and write to file or stream
    byte[] fileContent = new byte[fileSpecification.Contents.Length];
    fileSpecification.Contents.Read(fileContent, 0, fileContent.Length);

    FileStream fileStream = new FileStream(fileSpecification.Name, FileMode.Create);
    fileStream.Write(fileContent, 0, fileContent.Length);
    fileStream.Close();
}

remove-attachment.cs

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// Open document
Document pdfDocument = new Document("document.pdf");

// Delete all attachments
pdfDocument.EmbeddedFiles.Delete();

// Save updated file
pdfDocument.Save("output.pdf");