用MFC实现最基本的画图功能。。。 包括画点、直线、椭圆、矩形、橡皮等。。。 可以更换画笔颜色。。。 可以取反色-Using MFC to achieve the most basic drawing functions. . . Including drawing points, lines, ovals, rectangles, rubber and so on. . . You can replace the pen color. . . You can in