How to force window to redraw?

Question

I have a full-screen window, using this code:

WindowStyle = System.Windows.WindowStyle.None;
WindowState = System.Windows.WindowState.Maximized;
Topmost = true;

It works ok under Win7, but under WinXP some window elements don't get redrawn when the window goes fullscreen. Is there any way to force window to make full redraw and layout update?

UPD all is redrawn ok, if I switch to another app with Atl-Tab and then back to mine

Any chance this is related to your case as well? http://stackoverflow.com/questions/122857/wpf-transparent-borders-causes-the-ui-to-stop-redrawing — Shadow The GPT Wizard, Apr 11 '11 at 14:45
http://msdn.microsoft.com/en-us/library/system.windows.uielement.invalidatevisual.aspx — gandjustas, Apr 11 '11 at 14:33
Unfortunately, it doesn't seem to work in this case. The problem persists. — user626528, Apr 11 '11 at 14:41

score 6 · Accepted Answer · answered Jul 12 '12 at 23:54

You could force the window to repaint by using the Windows API.

Example class implementation:

public static class WindowsApi
{
    private const int WmPaint = 0x000F;

    [DllImport("User32.dll")]
    public static extern Int64 SendMessage(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);

    public static void ForcePaint(this Form form)
    {
        SendMessage(form.Handle, WmPaint, IntPtr.Zero, IntPtr.Zero);
    }
}

Usage:

Form testForm = new Form();
testForm.ForcePaint();

How to force window to redraw?

1 Answers1