EVO HTML to PDF Converter allows you add elements in PDF pages background in HtmlToPdfConverterBeforeRenderPdfPageEvent event handler which is called right before the main content of the PDF page is rendered by converter.
Code Sample - Add Elements in PDF Pages Background
protected void convertToPdfButton_Click(object sender, EventArgs e) { // Create a HTML to PDF converter object with default settings HtmlToPdfConverter 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 = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c="; // 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 htmlToPdfConverter.BeforeRenderPdfPageEvent += new BeforeRenderPdfPageDelegate(htmlToPdfConverter_BeforeRenderPdfPageEvent); try { // The buffer to receive the generated PDF document byte[] outPdfBuffer = null; if (convertUrlRadioButton.Checked) { string url = urlTextBox.Text; // Convert the HTML page given by an URL to a PDF document in a memory buffer outPdfBuffer = htmlToPdfConverter.ConvertUrl(url); } else { string htmlString = htmlStringTextBox.Text; string baseUrl = baseUrlTextBox.Text; // Convert a HTML string with a base URL to a PDF document in a memory buffer outPdfBuffer = htmlToPdfConverter.ConvertHtml(htmlString, baseUrl); } // Send the PDF as response to browser // Set response content type Response.AddHeader("Content-Type", "application/pdf"); // Instruct the browser to open the PDF file as an attachment or inline Response.AddHeader("Content-Disposition", String.Format("attachment; filename=Add_Elements_in_Background.pdf; size={0}", outPdfBuffer.Length.ToString())); // Write the PDF document buffer to HTTP response Response.BinaryWrite(outPdfBuffer); // End the HTTP response and stop the current page processing Response.End(); } finally { // Uninstall the handler htmlToPdfConverter.BeforeRenderPdfPageEvent -= new BeforeRenderPdfPageDelegate(htmlToPdfConverter_BeforeRenderPdfPageEvent); } } /// <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> void htmlToPdfConverter_BeforeRenderPdfPageEvent(BeforeRenderPdfPageParams eventParams) { if (!addBackgroundImageCheckBox.Checked) return; // Get the PDF page being rendered PdfPage pdfPage = eventParams.Page; // Get the PDF page drawable area width and height float pdfPageWidth = pdfPage.ClientRectangle.Width; float pdfPageHeight = pdfPage.ClientRectangle.Height; // The image to be added as background string backgroundImagePath = Server.MapPath("~/DemoAppFiles/Input/Images/background.jpg"); // The image element to add in background ImageElement backgroundImageElement = 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); }