ActiveBrowser.Capture produces black image if screen is not visible

2 posts, 0 answers
  1. Hussam Zawil
    Hussam Zawil avatar
    1 posts
    Member since:
    May 2010

    Posted 25 Jul 2011 Link to this post

    I'm using the latest Telerik WebAii Testing Framework (2011_2_712). Our automation code uses ActiveBrowser.Capture to capture an
    image of the browser if the test fails. Our automation uses multiple windowless clients VMs (Windows Server 2008 R2 Standard).
    If I remote desktop into these VMs to view the browser window while tests are running, ActiveBrowser.Capture works fine and produces the correct image. However, if I do not remote desktop into the machine and ensure that the browser running the tests is visible, or minimize the remote desktop window, then a black image is always produced.  I even tried doing multiple calls to ActiveBrowser.Capture  with a 1 sec delay between them as recommended by some posts and saving the image into different formats (jpeg, gif, bmp, png) but they all produced black image.

    I saw many posts regarding this problem and it is due to older versions of WebAii framework using the Windows screenshot to capture an image and that requires the browser to be visible. I thought that the latest release fixed that, but apparently not.

    Here is the code I'm using:
                    System.Drawing.Bitmap browserImage = ActiveBrowser.Capture();
                    if (browserImage != null)
                        var fileName = TestCaseName + "_" + DateTime.Now.ToString("MM_dd_yyyy_HH_mm_ss_ffff");
                        fileName = Path.ChangeExtension(Path.Combine(directory.FullName, fileName), ".png");
                        browserImage.Save(fileName, ImageFormat.Png);

    Is there any other suggestions I can do to make this work? Keeping active Remote Desktop Connections to each client VM is not an option. I've attached a sample image of the black capture of browser.
    Thanks for any help you can provide.
  2. Cody
    Cody avatar
    3354 posts

    Posted 27 Jul 2011 Link to this post

    Hi Hussam Zawil,

    I've heard of some customers having success using a VNC product instead of using Remote Desktop. I don't have a specific one to recommend, but there are multiple VNC products available on the market today.

    I have filed a bug report on this here.

    All the best,
    the Telerik team
    Check out the Test Studio roadmap to find out more about the new performance testing functionality coming in our R2 2011 release this September!

    Have you looked at the new Online User Guide for Telerik Test Studio?
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