BOOL LineDDA(
int nXStart, // x-coordinate of line's starting point
int nYStart, // y-coordinate of line's starting point
int nXEnd, // x-coordinate of line's ending point
int nYEnd, // y-coordinate of line's ending point
LINEDDAPROC lpLineFunc, // address of application-defined callback function
LPARAM lpData // address of application-defined data
);
在lpLineFunc中画图片