' Define the HTML to PDF converter object as a class member to make it accessible in the headerHtml_NavigationCompletedEvent handler ' where the header height will be automatically adjusted Private htmlToPdfConverter As HtmlToPdfConverter ' Indicates if a line should be drawn at the botom of the header Private drawHeaderLine As Boolean = True 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 htmlToPdfConverter = 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=" ' Enable header in the generated PDF document htmlToPdfConverter.PdfDocumentOptions.ShowHeader = True Cursor = Cursors.WaitCursor Dim headerHtmlUrl As String = System.IO.Path.Combine(Application.StartupPath, "DemoAppFiles\Input\HTML_Files\Header_HTML.html") Dim outPdfFile As String = "DemoAppFiles\Output\HTML_to_PDF\Auto_Resize_Header_Footer.pdf" Dim documentObject As Document = Nothing Try If autoResizeHeaderRadioButton.Checked Then ' Create a HTML element to be added in header Dim headerHtml As New HtmlToPdfElement(headerHtmlUrl) ' Install a handler where to set the automatically calculated header height AddHandler headerHtml.NavigationCompletedEvent, AddressOf headerHtml_NavigationCompletedEvent ' Add the HTML element to header ' When the element is rendered in header by converter, the headerHtml_NavigationCompletedEvent handler ' will be invoked and the header height will be automatically calculated htmlToPdfConverter.PdfHeaderOptions.AddElement(headerHtml) ' Call the converter to produce a Document object documentObject = htmlToPdfConverter.ConvertUrlToPdfDocumentObject(urlTextBox.Text) ' Uninstall the handler RemoveHandler headerHtml.NavigationCompletedEvent, AddressOf headerHtml_NavigationCompletedEvent ' Draw a line at the header bottom If drawHeaderLine Then Dim headerWidth As Single = documentObject.Header.Width Dim headerHeight As Single = documentObject.Header.Height ' Create a line element for the bottom of the header Dim headerLine As New LineElement(0, headerHeight - 1, headerWidth, headerHeight - 1) ' Set line color headerLine.ForeColor = Color.Gray ' Add line element to the bottom of the header documentObject.Header.AddElement(headerLine) End If ' Save the PDF document in a memory buffer Dim outPdfBuffer() As Byte = documentObject.Save() ' Write the memory buffer in a PDF file System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer) Else ' Create a HTML to PDF element to be added in header Dim headerHtml As New HtmlToPdfElement(headerHtmlUrl) ' Set a fixed header height in points htmlToPdfConverter.PdfHeaderOptions.HeaderHeight = Single.Parse(headerHeightTextBox.Text) ' Set the HTML element to fit the container height headerHtml.FitHeight = True ' Add HTML element to fit the fixed header height htmlToPdfConverter.PdfHeaderOptions.AddElement(headerHtml) ' Draw a line at the header bottom If drawHeaderLine Then ' Calculate the header width based on PDF page size and margins Dim headerWidth As Single = htmlToPdfConverter.PdfDocumentOptions.PdfPageSize.Width - htmlToPdfConverter.PdfDocumentOptions.LeftMargin - htmlToPdfConverter.PdfDocumentOptions.RightMargin ' Calculate header height Dim headerHeight As Single = htmlToPdfConverter.PdfHeaderOptions.HeaderHeight ' Create a line element for the bottom of the header Dim headerLine As New LineElement(0, headerHeight - 1, headerWidth, headerHeight - 1) ' Set line color headerLine.ForeColor = Color.Gray ' Add line element to the bottom of the header htmlToPdfConverter.PdfHeaderOptions.AddElement(headerLine) End If ' Convert the HTML page to a PDF document in a memory buffer Dim outPdfBuffer() As Byte = htmlToPdfConverter.ConvertUrl(urlTextBox.Text) ' 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 ' Close the PDF document If documentObject IsNot Nothing Then documentObject.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 ''' <summary> ''' This handler is called after the navigation to header HTML completed. The document header is resized in this event handler ''' </summary> ''' <param name="eventParams">The event parameter containing the HTML content size in pixels and points</param> Private Sub headerHtml_NavigationCompletedEvent(ByVal eventParams As NavigationCompletedParams) ' Get the header HTML width and height from event parameters Dim headerHtmlWidth As Single = eventParams.HtmlContentWidthPt Dim headerHtmlHeight As Single = eventParams.HtmlContentHeightPt ' Calculate the header width from coverter settings Dim headerWidth As Single = htmlToPdfConverter.PdfDocumentOptions.PdfPageSize.Width - htmlToPdfConverter.PdfDocumentOptions.LeftMargin - htmlToPdfConverter.PdfDocumentOptions.RightMargin ' Calculate a resize factor to fit the header width Dim resizeFactor As Single = 1 If headerHtmlWidth > headerWidth Then resizeFactor = headerWidth / headerHtmlWidth End If ' Calculate the header height to preserve the HTML aspect ratio Dim headerHeight As Single = headerHtmlHeight * resizeFactor If Not (headerHeight < htmlToPdfConverter.PdfDocumentOptions.PdfPageSize.Height - htmlToPdfConverter.PdfDocumentOptions.TopMargin - htmlToPdfConverter.PdfDocumentOptions.BottomMargin) Then Throw New Exception("The header height cannot be bigger than PDF page height") End If ' Set the calculated header height htmlToPdfConverter.PdfDocumentOptions.DocumentObject.Header.Height = headerHeight End Sub