PrintWindow WPF / DirectX

Question

Anyone know of a way to reliably take a snapshot of a WPF window? The PrintWindow api works well for "standard" win32 windows but since WPF uses DirectX, PrintWindow fails to capture an image. I think that one would need to grab the front buffer for the DirectX object associated with the window, but I am not sure how to do that.

Thanks!

Answer 1

I'm not sure if this is what you mean, and I'm not sure I'm allowed to link to my blog or not, but is this any use? It basically uses a RenderTargetBitmap to generate a JPG. You can use it to "screenshot" an entire window then print that.

If this is against the rules, someone feel free to delete :)

Answer 2

This Method should help you print the entire WPF / XAML Window

private void PrintWindow(PrintDialog pdPrint, 
                         System.Windows.Window wWin, 
                         string sTitle, 
                         System.Windows.Thickness? thMargin)
    {
        Grid drawing_area = new Grid();
        drawing_area.Width = pdPrint.PrintableAreaWidth;
        drawing_area.Height = pdPrint.PrintableAreaHeight;


        Viewbox view_box = new Viewbox();
        drawing_area.Children.Add(view_box);
        view_box.HorizontalAlignment = System.Windows.HorizontalAlignment.Center;
        view_box.VerticalAlignment = System.Windows.VerticalAlignment.Center;

        if (thMargin == null)
        {
            view_box.Stretch = System.Windows.Media.Stretch.None;
        }
        else
        {

            view_box.Margin = thMargin.Value;
            view_box.Stretch = System.Windows.Media.Stretch.Uniform;
        }


        VisualBrush vis_br = new VisualBrush(wWin);


        System.Windows.Shapes.Rectangle win_rect = new System.Windows.Shapes.Rectangle();
        view_box.Child = win_rect;
        win_rect.Width = wWin.Width;
        win_rect.Height = wWin.Height;
        win_rect.Fill = vis_br;
        win_rect.Stroke = System.Windows.Media.Brushes.Black;
        win_rect.BitmapEffect = new System.Windows.Media.Effects.DropShadowBitmapEffect();

        // Arrange to produce output.
        Rect rect = new Rect(0, 0, pdPrint.PrintableAreaWidth, pdPrint.PrintableAreaHeight);
        drawing_area.Arrange(rect);

        // Print it.
        pdPrint.PrintVisual(drawing_area, sTitle);

    }

Regards Sean Campbell