private static RECT GetClientRectRelativeToWindowRect(IntPtr hwnd)
{
RECT lpRect1;
NativeMethods.GetWindowRect(hwnd, out lpRect1);
RECT lpRect2;
NativeMethods.GetClientRect(hwnd, out lpRect2);
var point = new Core.Platform.Point {
X = 0, Y = 0
};
NativeMethods.ClientToScreen(hwnd, ref point);
lpRect2.Offset(point.X - lpRect1.Left, point.Y - lpRect1.Top);
return(lpRect2);
}