แสตมป์ในรูปแบบ PDF ผ่าน C#

    // Open document
    Document pdfDocument = new Document(dataDir+ "AddTextStamp.pdf");

    // Create text stamp
    TextStamp textStamp = new TextStamp("Sample Stamp");
    // Set whether stamp is background
    textStamp.Background = true;
    // Set origin
    textStamp.XIndent = 100;
    textStamp.YIndent = 100;
    // Rotate stamp
    textStamp.Rotate = Rotation.on90;
    // Set text properties
    textStamp.TextState.Font = FontRepository.FindFont("Arial");
    textStamp.TextState.FontSize = 14.0F;
    textStamp.TextState.FontStyle = FontStyles.Bold;
    textStamp.TextState.FontStyle = FontStyles.Italic;
    textStamp.TextState.ForegroundColor = Aspose.Pdf.Color.FromRgb(System.Drawing.Color.Aqua);
    // Add stamp to particular page
    pdfDocument.Pages[1].AddStamp(textStamp);

    dataDir = dataDir + "AddTextStamp_out.pdf";
    // Save output document
    pdfDocument.Save(dataDir);