EVO HTML to PDF Converter

Convert HTML to Raster Image

EVO HTML to PDF Converter for .NET Documentation

EVO HTML to PDF Converter also allows you to easily convert in just a few lines of code HTML pages and HTML strings to raster images in PNG, JPG or BMP format. In this section you can learn about the basic settings of the converter.

You can choose the HTML document to convert which can be:

The basic options you can set are grouped in a few categories.

HTML Viewer Options

  • HTML Viewer Width. This option is the equivalent in converter of the browser window width. The property you can set in your code to control the browser window width is HtmlToImageConverterHtmlViewerWidth. When the browser window width is changed the HTML content displayed inside the window can have a different layout and something similar happens when you change the HTML Viewer width of the converter. At a given viewer width, the converter will capture by default the whole height of the HTML content, but you can set the HTML Viewer height to capture only the top part of the HTML page

  • HTML Viewer Height. This option is the equivalent in converter of the browser window height and can be used to limit the conversion to the top part of the HTML page. If this property is not set the entire page will be converted. The property you can set in your code to control the browser window height is HtmlToImageConverterHtmlViewerHeight

Image Options

Navigation Options

Code Sample - Convert HTML to Raster Image

protected void convertToImageButton_Click(object sender, EventArgs e)
{
    // Create a HTML to Image converter object with default settings
    HtmlToImageConverter htmlToImageConverter = new HtmlToImageConverter();

    // Set license key received after purchase to use the converter in licensed mode
    // Leave it not set to use the converter in demo mode
    htmlToImageConverter.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

    // Set HTML Viewer width in pixels which is the equivalent in converter of the browser window width
    htmlToImageConverter.HtmlViewerWidth = int.Parse(htmlViewerWidthTextBox.Text);

    // Set HTML viewer height in pixels to convert the top part of a HTML page 
    // Leave it not set to convert the entire HTML
    if (htmlViewerHeightTextBox.Text.Length > 0)
        htmlToImageConverter.HtmlViewerHeight = int.Parse(htmlViewerHeightTextBox.Text);

    // Set if the created image has a transparent background
    htmlToImageConverter.TransparentBackground = SelectedImageFormat() == System.Drawing.Imaging.ImageFormat.Png ? transparentBackgroundCheckBox.Checked : false;

    // Set the maximum time in seconds to wait for HTML page to be loaded 
    // Leave it not set for a default 60 seconds maximum wait time
    htmlToImageConverter.NavigationTimeout = int.Parse(navigationTimeoutTextBox.Text);

    // 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
    if (conversionDelayTextBox.Text.Length > 0)
        htmlToImageConverter.ConversionDelay = int.Parse(conversionDelayTextBox.Text);

    System.Drawing.Image[] imageTiles = null;

    if (convertUrlRadioButton.Checked)
    {
        string url = urlTextBox.Text;

        // Convert the HTML page given by an URL to a set of Image objects
        imageTiles = htmlToImageConverter.ConvertUrlToImageTiles(url);
    }
    else
    {
        string htmlString = htmlStringTextBox.Text;
        string baseUrl = baseUrlTextBox.Text;

        // Convert a HTML string with a base URL to a set of Image objects
        imageTiles = htmlToImageConverter.ConvertHtmlToImageTiles(htmlString, baseUrl);
    }

    // Save the first image tile to a memory buffer

    System.Drawing.Image outImage = imageTiles[0];

    // Create a memory stream where to save the image
    System.IO.MemoryStream imageOutputStream = new System.IO.MemoryStream();

    // Save the image to memory stream
    outImage.Save(imageOutputStream, SelectedImageFormat());

    // Write the memory stream to a memory buffer
    imageOutputStream.Position = 0;
    byte[] outImageBuffer = imageOutputStream.ToArray();

    // Close the output memory stream
    imageOutputStream.Close();

    // Send the image as response to browser

    string imageFormatName = imageFormatComboBox.SelectedValue.ToLower();

    // Set response content type
    Response.AddHeader("Content-Type", "image/" + (imageFormatName == "jpg" ? "jpeg" : imageFormatName));

    // Instruct the browser to open the image file as an attachment or inline
    Response.AddHeader("Content-Disposition", String.Format("attachment; filename={0}; size={1}", "HTML_to_Image." + imageFormatName, outImageBuffer.Length.ToString()));

    // Write the image buffer to HTTP response
    Response.BinaryWrite(outImageBuffer);

    // End the HTTP response and stop the current page processing
    Response.End();
}