Imports System.Drawing
Imports Vintasoft.Imaging.Pdf

''' <summary>
''' Adds empty signature field to a PDF page.
''' </summary>
Public Class PdfPageDigitalSignatureHelper_EmptySignatureField
    ''' <summary>
    ''' Adds an empty signature field to PDF document.
    ''' </summary>
    ''' <param name="inputFilename">The name of input PDF file.</param>
    ''' <param name="outputFilename">The name of output PDF file.</param>
    Public Shared Sub AddEmptySignatureField(inputFilename As String, outputFilename As String)
        ' create a helper that alows to add digital signature to a PDF document
        Dim digitalSignatureHelper As New PdfPageDigitalSignatureHelper(Nothing, New RectangleF(20, 20, 250, 100))

        ' set the appearance for signature field
        digitalSignatureHelper.SignatureText = "Add your signature here"
        digitalSignatureHelper.SignatureBackgoundColor = Color.Yellow

        ' open PDF document
        Using document As New PdfDocument(inputFilename)
            ' add signature field to the first PDF page
            digitalSignatureHelper.AddEmptySignatureField(document.Pages(0))

            ' save PDF document to the output file
            document.SaveChanges("TestDocumentToSign-output.pdf")
        End Using
    End Sub
End Class

using System.Drawing;
using Vintasoft.Imaging.Pdf;

/// <summary>
/// Adds empty signature field to a PDF page.
/// </summary>
public class PdfPageDigitalSignatureHelper_EmptySignatureField
{
    /// <summary>
    /// Adds an empty signature field to PDF document.
    /// </summary>
    /// <param name="inputFilename">The name of input PDF file.</param>
    /// <param name="outputFilename">The name of output PDF file.</param>
    public static void AddEmptySignatureField(
        string inputFilename,
        string outputFilename)
    {
        // create a helper that alows to add digital signature to a PDF document
        PdfPageDigitalSignatureHelper digitalSignatureHelper = new PdfPageDigitalSignatureHelper(null, new RectangleF(20, 20, 250, 100));

        // set the appearance for signature field
        digitalSignatureHelper.SignatureText = "Add your signature here";
        digitalSignatureHelper.SignatureBackgoundColor = Color.Yellow;

        // open PDF document
        using (PdfDocument document = new PdfDocument(inputFilename))
        {
            // add signature field to the first PDF page
            digitalSignatureHelper.AddEmptySignatureField(document.Pages[0]);

            // save PDF document to the output file
            document.SaveChanges("TestDocumentToSign-output.pdf");
        }
    }
}