Imports System.Drawing
Imports System.Security.Cryptography.X509Certificates
Imports Vintasoft.Imaging.Pdf

''' <summary>
''' Adds digital signature with text appearance to a PDF page.
''' </summary>
Public Class PdfPageDigitalSignatureHelper_TextAppearance
    ''' <summary>
    ''' Signs a PDF document using specified PFX file.
    ''' </summary>
    ''' <param name="inputFilename">The name of input PDF file.</param>
    ''' <param name="outputFilename">The name of output PDF file.</param>
    ''' <param name="pfxFileName">The name of PFX file.</param>
    ''' <param name="pfxFilePassword">The password for PDF file.</param>
    Public Shared Sub SignPdfDocument(inputFilename As String, outputFilename As String, pfxFileName As String, pfxFilePassword As String)
        ' get the X509 certificate from .pfx-file
        Using certificate As New X509Certificate2(pfxFileName, pfxFileName)
            ' create a helper that alows to add digital signature to a PDF document
            Dim digitalSignatureHelper As New PdfPageDigitalSignatureHelper(certificate, New RectangleF(20, 20, 250, 100))

            ' set the reason for signing
            digitalSignatureHelper.SigningReason = "Approve document"

            ' set the signature appearance text
            digitalSignatureHelper.SignatureText = String.Format("Digitally signed by" & vbLf & "{0}", digitalSignatureHelper.SignerName)

            ' add digital signature to the first PDF page, sign PDF document and save PDF document to the output file
            digitalSignatureHelper.SignDocument(inputFilename, outputFilename, 0)
        End Using
    End Sub
End Class

using System.Drawing;
using System.Security.Cryptography.X509Certificates;
using Vintasoft.Imaging.Pdf;

/// <summary>
/// Adds digital signature with text appearance to a PDF page.
/// </summary>
public class PdfPageDigitalSignatureHelper_TextAppearance
{
    /// <summary>
    /// Signs a PDF document using specified PFX file.
    /// </summary>
    /// <param name="inputFilename">The name of input PDF file.</param>
    /// <param name="outputFilename">The name of output PDF file.</param>
    /// <param name="pfxFileName">The name of PFX file.</param>
    /// <param name="pfxFilePassword">The password for PDF file.</param>
    public static void SignPdfDocument(
        string inputFilename,
        string outputFilename,
        string pfxFileName,
        string pfxFilePassword)
    {
        // get the X509 certificate from .pfx-file
        using (X509Certificate2 certificate = new X509Certificate2(pfxFileName, pfxFileName))
        {
            // create a helper that alows to add digital signature to a PDF document
            PdfPageDigitalSignatureHelper digitalSignatureHelper = new PdfPageDigitalSignatureHelper(certificate, new RectangleF(20, 20, 250, 100));

            // set the reason for signing
            digitalSignatureHelper.SigningReason = "Approve document";

            // set the signature appearance text
            digitalSignatureHelper.SignatureText = string.Format("Digitally signed by\n{0}", digitalSignatureHelper.SignerName);

            // add digital signature to the first PDF page, sign PDF document and save PDF document to the output file
            digitalSignatureHelper.SignDocument(inputFilename, outputFilename, 0);
        }
    }
}