/// <devdoc>
/// </devdoc>
/// <internalonly/>
private void SetWindowRgn()
{
IntPtr rgn1 = IntPtr.Zero;
IntPtr rgn2 = IntPtr.Zero;
NativeMethods.RECT rect = new NativeMethods.RECT();
CreateParams cp = CreateParams;
SafeNativeMethods.AdjustWindowRectEx(ref rect, cp.Style, false, cp.ExStyle);
Rectangle bounds = Bounds;
rgn1 = SafeNativeMethods.CreateRectRgn(0, 0, bounds.Width, bounds.Height);
try {
rgn2 = SafeNativeMethods.CreateRectRgn(-rect.left, -rect.top,
bounds.Width - rect.right, bounds.Height - rect.bottom);
try {
if (rgn1 == IntPtr.Zero || rgn2 == IntPtr.Zero)
{
throw new InvalidOperationException(SR.GetString(SR.ErrorSettingWindowRegion));
}
if (SafeNativeMethods.CombineRgn(new HandleRef(null, rgn1), new HandleRef(null, rgn1), new HandleRef(null, rgn2), NativeMethods.RGN_DIFF) == 0)
{
throw new InvalidOperationException(SR.GetString(SR.ErrorSettingWindowRegion));
}
if (UnsafeNativeMethods.SetWindowRgn(new HandleRef(this, Handle), new HandleRef(null, rgn1), true) == 0)
{
throw new InvalidOperationException(SR.GetString(SR.ErrorSettingWindowRegion));
}
else
{
// The hwnd now owns the region.
rgn1 = IntPtr.Zero;
}
}
finally {
if (rgn2 != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(new HandleRef(null, rgn2));
}
}
}
finally {
if (rgn1 != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(new HandleRef(null, rgn1));
}
}
}