public static extern void DwmExtendFrameIntoClientArea(IntPtr hWnd, ref Margin pMargins);
        private void ExtendFrameIntoClient()
        {
            _margin = new Margin
            {
                cxLeftWidth = X,
                cxRightWidth = Width,
                cyBottomHeight = Height,
                cyTopHeight = Y
            };

            NativeMethods.DwmExtendFrameIntoClientArea(Handle, ref _margin);
        }