Issues when making a screenshot

2 posts, 0 answers
  1. Carlos
    Carlos avatar
    1 posts
    Member since:
    May 2014

    Posted 12 Jan Link to this post

    I have the following extension method in my application. It captures previews of my usercontrols and allows the user to navigate them via a menu.


    /// <summary>
    /// Renders a framework element as a bitmap image.
    /// </summary>
    /// <param name="frameworkElement">The framework element to be rendered.</param>
    /// <param name="background">The background to be applied to the element, in case the element has trasnparent background.</param>
    /// <param name="scale">The scaling of the image, default should be 1.</param>
    /// <returns>The image as a scaled bitmap.</returns>
    public static BitmapImage RenderToBitmap(this FrameworkElement frameworkElement, Brush background, double scale = 1)
        Check.NotNull(frameworkElement, "frameworkElement");
        var renderWidth = (int)(frameworkElement.RenderSize.Width * scale);
        var renderHeight = (int)(frameworkElement.RenderSize.Height * scale);
        if (renderWidth > 0 && renderHeight > 0)
            var renderTarget = new RenderTargetBitmap(renderWidth, renderHeight, 96, 96, PixelFormats.Default);
            var sourceBrush = new VisualBrush(frameworkElement);
            var drawingVisual = new DrawingVisual();
            var rect = new Rect(new Point(0, 0), new Point(frameworkElement.RenderSize.Width, frameworkElement.RenderSize.Height));
            using (var drawingContext = drawingVisual.RenderOpen())
                drawingContext.PushTransform(new ScaleTransform(scale, scale));
                drawingContext.DrawRectangle(background, null, rect);
                drawingContext.DrawRectangle(sourceBrush, null, rect);
            var image = new BitmapImage();
            using (MemoryStream memoryStream = new MemoryStream())
                JpegBitmapEncoder encoder = new JpegBitmapEncoder();
                image.StreamSource = new MemoryStream(memoryStream.ToArray());
            return image;
        return null;


    Lately we've started a new development with the radmap control and we started to have some issues. The app hanged whenever we entered the view containing the map. I profiled the app and the results tell me that there's an issue with the radmap control.


    I've started trying stuff and I realized that the problem starts when I try to generate the visual before the image creation. If I instead do renderTarget.Render(frameworkElement) it seems to work, but then I can't apply the background transformation to the visual. The problem starts when I use the map to create a VisualBrush. Could this be a bug? 


    Thanks for your time.



  2. Petar Mladenov
    Petar Mladenov avatar
    2882 posts

    Posted 15 Jan Link to this post

    Hello Carlos,

    Please send us some more code showing the way you use this method with RadMap and especially what you use in RadMap:
    - - which map provider - Bing /OopenStreet ?
    - - which map layer - ItemInformationLayer / VisualizationLayer ?
    - - do you add shapes - map shape data , framework elements, how many ?
    We will then try to reproduce such error on our side.

    Petar Mladenov
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