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

    ' Set a handler for BeforeRenderPdfPageEvent where to set the background image in each PDF page before main content is rendered
    AddHandler htmlToPdfConverter.BeforeRenderPdfPageEvent, AddressOf htmlToPdfConverter_BeforeRenderPdfPageEvent

    Cursor = Cursors.WaitCursor

    Dim outPdfFile As String = "DemoAppFiles\Output\HTML_to_PDF\Add_Elements_in_Background.pdf"
    Try
        If convertUrlRadioButton.Checked Then
            Dim url As String = urlTextBox.Text

            ' Convert the HTML page given by an URL to a PDF document in a memory buffer
            Dim outPdfBuffer() As Byte = htmlToPdfConverter.ConvertUrl(url)

            ' Write the memory buffer in a PDF file
            System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer)
        Else
            Dim htmlString As String = htmlStringTextBox.Text
            Dim baseUrl As String = baseUrlTextBox.Text

            ' Convert a HTML string with a base URL to a PDF document in a memory buffer
            Dim outPdfBuffer() As Byte = htmlToPdfConverter.ConvertHtml(htmlString, baseUrl)

            ' Write the memory buffer in a PDF file
            System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer)
        End If
    Catch ex As Exception
        ' The HTML to PDF conversion failed
        MessageBox.Show(String.Format("HTML to PDF Error. {0}", ex.Message))
        Return
    Finally
        Cursor = Cursors.Arrow

        ' Uninstall the handler
        RemoveHandler htmlToPdfConverter.BeforeRenderPdfPageEvent, AddressOf htmlToPdfConverter_BeforeRenderPdfPageEvent
    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

''' <summary>
''' The BeforeRenderPdfPageEvent event handler where a background image is set in each PDF page
''' before the main content is rendered
''' </summary>
''' <param name="eventParams">The event parameter containing the PDF page being rendered</param>
Private Sub htmlToPdfConverter_BeforeRenderPdfPageEvent(ByVal eventParams As BeforeRenderPdfPageParams)
    If Not addBackgroundImageCheckBox.Checked Then
        Return
    End If

    ' Get the PDF page being rendered
    Dim pdfPage As PdfPage = eventParams.Page

    ' Get the PDF page drawable area width and height
    Dim pdfPageWidth As Single = pdfPage.ClientRectangle.Width
    Dim pdfPageHeight As Single = pdfPage.ClientRectangle.Height

    ' The image to be added as background
    Dim backgroundImagePath As String = "DemoAppFiles\Input\Images\background.jpg"

    ' The image element to add in background
    Dim backgroundImageElement As New ImageElement(0, 0, pdfPageWidth, pdfPageHeight, backgroundImagePath)
    backgroundImageElement.KeepAspectRatio = True
    backgroundImageElement.EnlargeEnabled = True

    ' Add the background image element to PDF page before the main content is rendered
    pdfPage.AddElement(backgroundImageElement)
End Sub