Bounce_Ball

代码说明：

  弹球程序。编写程序，该程序通过一个发射按钮可以发射一个弹球，该球遇到边界时会自动弹回，在移动固定次数后，该球停止运动。要求每次点击发射按钮都会发射一个弹球，如果点击多次，则多个弹球同时运动。该程序通过另一个结束可以结束程序的运行。(Pinball program. Write a program, the program can be launched via a launch button a pinball, the ball across the boundary will automatically spring back after a fixed number of moving the ball stops moving. Requires each click launch button will launch a pinball, if you click multiple times, multiple pinball simultaneous movement. Another end of the program through the end of the program can be run.)