public static extern int BitBlt(
IntPtr hdcDest, // handle to destination DC (device context)
int nXDest, // x-coord of destination upper-left corner
int nYDest, // y-coord of destination upper-left corner
int nWidth, // width of destination rectangle
int nHeight, // height of destination rectangle
IntPtr hdcSrc, // handle to source DC
int nXSrc, // x-coordinate of source upper-left corner
int nYSrc, // y-coordinate of source upper-left corner
int dwRop // raster operation code
);