EVO HTML to PDF Converter

Add Elements in PDF Pages Background

EVO HTML to PDF Converter for .NET Documentation

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);
}