(C# UWP/WinRT) PDF Signature Appearance Text Substitution Keywords

See more PDF Signatures Examples

This example demonstrates the text substitution keywords that can be used in the PDF signature's appearance text.

Note: This example requires Chilkat v9.5.0.85 or greater.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.Pdf pdf = new Chilkat.Pdf();

// Load a PDF to be signed.
bool success = pdf.LoadFile("qa_data/pdf/empty.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

// Options for signing are specified in JSON.
Chilkat.JsonObject json = new Chilkat.JsonObject();

// In most cases, the signingCertificateV2 and signingTime attributes are required.
json.UpdateInt("signingCertificateV2",1);
json.UpdateInt("signingTime",1);

// Put the signature on page 1, top left
json.UpdateInt("page",1);
json.UpdateString("appearance.y","top");
json.UpdateString("appearance.x","left");

// Use a font scale of 7.0
json.UpdateString("appearance.fontScale","7.0");

// The appearance of the PDF signature can contain any number of text lines.
// Chilkat has defined a number of special keywords that can be used in any text line.
// Each keyword is replaced with the actual value.
// For example, "cert_cn" is replaced with the certificate subject's common name (CN).

// Here we are creating a signature with many lines of text, to demonstrate each
// keyword.
json.UpdateString("appearance.text[0]","Date/time in PDF format: current_dt");
json.UpdateString("appearance.text[1]","Current Local date/time: current_datetime");
json.UpdateString("appearance.text[2]","GMT Timestamp: current_timestamp_gmt");
json.UpdateString("appearance.text[3]","Local Timestamp: current_timestamp_local");
json.UpdateString("appearance.text[4]","GMT RFC822 date/time: current_rfc822_dt_gmt");
json.UpdateString("appearance.text[5]","Local RFC822 date/time: current_rfc822_dt_local");
json.UpdateString("appearance.text[6]","Cert DN (Distinguished Name): cert_dn");
json.UpdateString("appearance.text[7]","Cert Common Name: cert_cn");
json.UpdateString("appearance.text[8]","Cert Organizational ID (2.5.4.97): cert_org_id");
json.UpdateString("appearance.text[9]","Cert Email: cert_email");
json.UpdateString("appearance.text[10]","Cert Organization: cert_organization");
json.UpdateString("appearance.text[11]","Cert Organziational Unit: cert_ou");
json.UpdateString("appearance.text[12]","Cert State: cert_state");
json.UpdateString("appearance.text[13]","Cert Country: cert_country");
json.UpdateString("appearance.text[14]","Cert Locality: cert_locality");
json.UpdateString("appearance.text[15]","Cert Serial Number (hex): cert_serial_hex");
json.UpdateString("appearance.text[16]","Cert Serial Number (decimal): cert_serial_dec");
json.UpdateString("appearance.text[17]","Cert Thumbprint: cert_thumbprint");
json.UpdateString("appearance.text[18]","Cert Issuer Common Name: cert_issuer_cn");

Chilkat.BinData jpgData = new Chilkat.BinData();
success = jpgData.LoadFile("qa_data/jpg/seal1.jpg");
if (success == false) {
    Debug.WriteLine("Failed to load the JPG image.");
    return;
}

success = pdf.SetSignatureJpeg(jpgData);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

// Specify that we want to display the JPG image in the center with 33% opacity.
json.UpdateString("appearance.image","custom-jpg");
json.UpdateString("appearance.imagePlacement","center");
json.UpdateString("appearance.imageOpacity","33");

// Load the signing certificate. (Use your own certificate.)
Chilkat.Cert cert = new Chilkat.Cert();
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","pfx_password");
if (success == false) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

// Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

success = await pdf.SignPdfAsync(json,"qa_output/hello_signed.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("The PDF has been successfully cryptographically signed.");

// The appearance of the signature appears in Adobe Acrobat as shown here: