internal static extern bool AlphaBlend(IntPtr hdcDest, int xoriginDest, int yoriginDest, int wDest, int hDest, IntPtr hdcSrc, int xoriginSrc, int yoriginSrc, int wSrc, int hSrc, BlendFunction pfn);
internal static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDest, ref POINT pptDest, ref Win32Size psize, IntPtr hdcSrc, ref POINT pptSrc, uint crKey, [In] ref BlendFunction pblend, uint dwFlags);