功能：可以绘制椭圆，矩形，直线，可更改绘制线条的类型，宽度，颜色等，有预览小窗口等简单的小操作，基于MFC。-Features: You can draw an ellipse, rectangle, line, you can change the type of line drawing, width, color, etc., there is a small preview window such as a simple little operation, based on the MF