编写一个单文档应用程序Sy2_2，在视图窗口中显示3个圆，通过使用不同颜色的画笔及画刷来模拟交通红绿灯。-Create a single document application Sy2_1, the program running, in the view window to draw a blue of the hollow circle in the view window to draw a red solid rectangle.