Latest release (June 2025)

// Initialize QR Code signing options
QrCodeSignOptions qrSignOptions = new QrCodeSignOptions("GROUP DOCS", QrCodeTypes.QR)
{
    Width = 250,                          // Width of the QR code
    Height = 270,                         // Height of the QR code
    ForeColor = Color.Red,                // Color of the QR code
    CodeTextAlignment = CodeTextAlignment.Below, // Text alignment relative to the QR code
    Text = "GROUP DOCS"                   // Text displayed below the QR code
};

// Configure preview generation options for the QR code signature
PreviewSignatureOptions previewOptions = new PreviewSignatureOptions(
    qrSignOptions,
    CreateSignatureStream,   // Delegate to create the stream
    ReleaseSignatureStream   // Delegate to release the stream
)
{
    SignatureId = Guid.NewGuid().ToString(),  // Unique identifier for the preview
    PreviewFormat = PreviewSignatureOptions.PreviewFormats.PNG  // Output format of preview
};

// Generate the signature preview image
Signature.GenerateSignaturePreview(previewOptions);

// Initialize barcode signing options with MaxiCode type
BarcodeSignOptions barcodeSignOptions = new BarcodeSignOptions("GROUP DOCS", BarcodeTypes.MaxiCode)
{
    Width = 400,                               // Width of the barcode
    Height = 400,                              // Height of the barcode
    ForeColor = Color.Red,                     // Foreground color of the barcode
    CodeTextAlignment = CodeTextAlignment.Below,  // Position of the text relative to the barcode
    Text = "GROUP DOCS",                       // Text displayed with the barcode
    RotationAngle = 45                         // Rotate the barcode by 45 degrees
};

// Configure preview generation options for the barcode signature
PreviewSignatureOptions previewOptions = new PreviewSignatureOptions(
    barcodeSignOptions,
    CreateSignatureStream,   // Delegate to create the output stream
    ReleaseSignatureStream   // Delegate to release the output stream
)
{
    SignatureId = Guid.NewGuid().ToString(),  // Unique identifier for the signature preview
    PreviewFormat = PreviewSignatureOptions.PreviewFormats.PNG  // Output preview format
};

// Generate the barcode signature preview image
Signature.GenerateSignaturePreview(previewOptions);

// Initialize barcode signing options with Codabar type
BarcodeSignOptions barcodeSignOptions = new BarcodeSignOptions("GROUP DOCS", BarcodeTypes.Codabar)
{
    Width = 400,                               // Width of the barcode preview
    Height = 400,                              // Height of the barcode preview
    ForeColor = Color.Red,                     // Foreground color of the barcode bars
    CodeTextAlignment = CodeTextAlignment.Below,  // Position text below the barcode
    Text = "GROUP DOCS",                       // Text displayed with the barcode
    Transparency = 0.5                         // Set barcode background transparency (50%)
};

// Configure preview generation options for the barcode signature
PreviewSignatureOptions previewOptions = new PreviewSignatureOptions(
    barcodeSignOptions,
    CreateSignatureStream,                     // Delegate to create the output stream
    ReleaseSignatureStream                     // Delegate to release the output stream
)
{
    SignatureId = Guid.NewGuid().ToString(),  // Unique identifier for this signature preview
    PreviewFormat = PreviewSignatureOptions.PreviewFormats.PNG  // Output preview format
};

// Generate the barcode signature preview image
Signature.GenerateSignaturePreview(previewOptions);

string signatureImagePath = "signature.png"
string certificatePath = "JohnSmithCertificate.pfx";

string inputPdf = "SampleDocument.pdf";
string outputPdf = "SignedDocument.pdf";

using (Signature signature = new Signature(inputPdf))
{
    DigitalSignOptions signOptions = new DigitalSignOptions(certificatePath)
    {
        Password = "1234567890",             // Certificate password
        Reason = "Document approval",       // Reason for signing
        Contact = "John Smith",              // Contact info
        Location = "Head Office",            // Signing location

        Visible = true,                      // Make signature visible on PDF
        Left = 350,                         // X coordinate of signature position
        Top = 100,                          // Y coordinate of signature position
        Width = 200,                       // Signature width
        Height = 70,                       // Signature height

        ImageFilePath = signatureImagePath, // Image to show inside signature

        Appearance = new PdfDigitalSignatureAppearance()
        {
            Foreground = Color.FromArgb(50, Color.Brown),    // Semi-transparent font color
            FontFamilyName = "Times New Roman",              // Font family
            FontSize = 12,                                    // Font size
            Background = Color.FromArgb(50, Color.LightGray),// Semi-transparent background
            IsForegroundImage = true                          // Image appears on top of text
        },
    };

    var signResult = signature.Sign(outputPdf, signOptions);

    Console.WriteLine($"\nDocument signed successfully with {signResult.Succeeded.Count} signature(s).");
    Console.WriteLine($"Signed file saved at: {outputPdf}");
}