1.　　编写一个单文档应用程序，程序启动后会在用户区显示一个方形，当用鼠标左键单击用户区时，方形会变成圆形，如果再单击则会又变回方形；

2.　　编写一个应用程序，该程序运行后会在用户区绘制一个圆形，没单击鼠标左键一次则圆的颜色会变化一次。

-1. Write a single document application, the program will start to display a square in the user area, click the left mouse button when the user area, the square will turn round, and then click will be changed again if returned to the square　2 . write an application, the program will run a circle drawn in the user area, no one will click the left mouse button will change the color of a circle.