private static WindowExtensions _EnsureAttachedExtensions(Window window)
{
Assert.IsNotNull(window);
var ext = (WindowExtensions)window.GetValue(WindowExtensionsProperty);
if (ext == null)
{
ext = new WindowExtensions(window);
window.SetValue(WindowExtensionsProperty, ext);
}
return(ext);
}
private static void _OnHwndBackgroundBrushChanged(DependencyObject d)
{
if (DesignerProperties.GetIsInDesignMode(d))
{
return;
}
var window = d as Window;
Verify.IsNotNull(window, "window");
WindowExtensions ext = _EnsureAttachedExtensions(window);
if (ext._hwnd == IntPtr.Zero)
{
ext.WindowSourceInitialized += () => _OnHwndBackgroundBrushChanged(window);
return;
}
SolidColorBrush backgroundBrush = (SolidColorBrush)window.GetValue(HwndBackgroundBrushProperty);
//if (backgroundBrush == null)
//{
// Nothing to change.
// return;
//}
Color backgroundColor = backgroundBrush.Color;
// Not really handling errors here, but they shouldn't matter... Might leak an HBRUSH.
IntPtr hBrush = NativeMethods.CreateSolidBrush(Utility.RGB(backgroundColor));
// Note that setting this doesn't necessarily repaint the window right away.
// Since the WPF content should cover the HWND background this doesn't matter.
// The new background will get repainted when the window is resized.
IntPtr hBrushOld = NativeMethods.SetClassLongPtr(ext._hwnd, GCLP.HBRBACKGROUND, hBrush);
if (IntPtr.Zero != hBrushOld)
{
NativeMethods.DeleteObject(hBrushOld);
}
}