private void _ExtendGlassFrame()
{
Assert.IsNotNull(_window);
// Expect that this might be called on OSes other than Vista.
if (!Utility.IsOSVistaOrNewer)
{
// Not an error. Just not on Vista so we're not going to get glass.
return;
}
if (IntPtr.Zero == _hwnd)
{
// Can't do anything with this call until the Window has been shown.
return;
}
// Ensure standard HWND background painting when DWM isn't enabled.
if (!NativeMethods.DwmIsCompositionEnabled())
{
_hwndSource.CompositionTarget.BackgroundColor = SystemColors.WindowColor;
}
else
{
// This makes the glass visible at a Win32 level so long as nothing else is covering it.
// The Window's Background needs to be changed independent of this.
// Apply the transparent background to the HWND
_hwndSource.CompositionTarget.BackgroundColor = Colors.Transparent;
// Thickness is going to be DIPs, need to convert to system coordinates.
var deviceTopLeft =
DpiHelper.LogicalPixelsToDevice(new Point(_chromeInfo.GlassFrameThickness.Left,
_chromeInfo.GlassFrameThickness.Top));
var deviceBottomRight =
DpiHelper.LogicalPixelsToDevice(new Point(_chromeInfo.GlassFrameThickness.Right,
_chromeInfo.GlassFrameThickness.Bottom));
var dwmMargin = new MARGINS
{
// err on the side of pushing in glass an extra pixel.
cxLeftWidth = (int)Math.Ceiling(deviceTopLeft.X),
cxRightWidth = (int)Math.Ceiling(deviceBottomRight.X),
cyTopHeight = (int)Math.Ceiling(deviceTopLeft.Y),
cyBottomHeight = (int)Math.Ceiling(deviceBottomRight.Y)
};
NativeMethods.DwmExtendFrameIntoClientArea(_hwnd, ref dwmMargin);
}
}
private void _RestoreGlassFrame()
{
Assert.IsNull(_chromeInfo);
Assert.IsNotNull(_window);
// Expect that this might be called on OSes other than Vista
// and if the window hasn't yet been shown, then we don't need to undo anything.
if (!Utility.IsOSVistaOrNewer || _hwnd == IntPtr.Zero)
{
return;
}
_hwndSource.CompositionTarget.BackgroundColor = SystemColors.WindowColor;
if (NativeMethods.DwmIsCompositionEnabled())
{
// If glass is enabled, push it back to the normal bounds.
var dwmMargin = new MARGINS();
NativeMethods.DwmExtendFrameIntoClientArea(_hwnd, ref dwmMargin);
}
}
public static extern void DwmExtendFrameIntoClientArea(IntPtr hwnd, ref MARGINS pMarInset);