Private Sub convertToPdfButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles convertToPdfButton.Click ' Create a HTML to PDF converter object with default settings Dim htmlToPdfConverter As New HtmlToPdfConverter() ' Set license key received after purchase to use the converter in licensed mode ' Leave it not set to use the converter in demo mode htmlToPdfConverter.LicenseKey = "fvDh8eDx4fHg4P/h8eLg/+Dj/+jo6Og=" ' Set an adddional delay in seconds to wait for JavaScript or AJAX calls after page load completed ' Set this property to 0 if you don't need to wait for such asynchcronous operations to finish htmlToPdfConverter.ConversionDelay = 2 Cursor = Cursors.WaitCursor Dim outPdfFile As String = "DemoAppFiles\Output\HTML_to_PDF\Digital_Signatures.pdf" Dim pdfDocument As Document = Nothing Try Dim htmlWithDigitalSignatureMarker As String = htmlStringTextBox.Text Dim baseUrl As String = baseUrlTextBox.Text ' Convert a HTML string with a marker for digital signature to a PDF document object pdfDocument = htmlToPdfConverter.ConvertHtmlToPdfDocumentObject(htmlWithDigitalSignatureMarker, baseUrl) ' Make the HTML element with 'digital_signature_element' mapping ID a link to digital signature properties Dim digitalSignatureMapping As HtmlElementMapping = htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult.GetElementByMappingId("digital_signature_element") If digitalSignatureMapping IsNot Nothing Then Dim digitalSignaturePage As PdfPage = digitalSignatureMapping.PdfRectangles(0).PdfPage Dim digitalSignatureRectangle As RectangleF = digitalSignatureMapping.PdfRectangles(0).Rectangle Dim certificateFilePath As String = "DemoAppFiles\Input\Certificates\wnvpdf.pfx" ' Get the certificate from password protected PFX file Dim certificates As DigitalCertificatesCollection = DigitalCertificatesStore.GetCertificates(certificateFilePath, "wnvpdf") Dim certificate As DigitalCertificate = certificates(0) ' Create the digital signature Dim signature As New DigitalSignatureElement(digitalSignatureRectangle, certificate) signature.Reason = "Protect the document from unwanted changes" signature.ContactInfo = "The contact email is support@winnovative-software.com" signature.Location = "Development server" digitalSignaturePage.AddElement(signature) End If ' Save the PDF document in a memory buffer Dim outPdfBuffer() As Byte = pdfDocument.Save() ' Write the memory buffer in a PDF file System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer) Catch ex As Exception ' The HTML to PDF conversion failed MessageBox.Show(String.Format("HTML to PDF Error. {0}", ex.Message)) Return Finally ' Close the PDF document If pdfDocument IsNot Nothing Then pdfDocument.Close() End If Cursor = Cursors.Arrow End Try ' Open the created PDF document in default PDF viewer Try Process.Start(outPdfFile) Catch ex As Exception MessageBox.Show(String.Format("Cannot open created PDF file '{0}'. {1}", outPdfFile, ex.Message)) End Try End Sub