public static extern int DrawTextEx( IntPtr hdc, string lpchText, int cchText, ref ssRECT lprc, uint dwDTFormat, ref ssDRAWTEXTPARAMS lpDTParams );
public static extern int FillRect( IntPtr HDC, ref ssRECT lprc, IntPtr hbr );
public static extern bool InvalidateRect( IntPtr hWnd, ref ssRECT lpRect, bool bErase);