一个画图板小程序，实现画矩形、椭圆、圆、折线、曲线等几何图形，各种颜色的画笔，可以用实线画，也可以用虚线画等等功能。-A drawing board a small program to achieve draw a rectangle, ellipse, round, broken line, curve and other geometric shapes, various colors of the brush, you can use solid line painting, paint