利用vc++编写的一个画板，通过选择画笔的颜色，能够画任意的直线，椭圆，矩形以及任意的线段。还能用橡皮擦工具清除所画的内容。-Using vc++ written a drawing board, by selecting the color of the pen, we can draw any straight line, oval, rectangular, and arbitrary line. Can also use the eraser tool to remove the con