本实例是一个类似于游戏的弹球程序，程序运行后，黄色的小球在白色的框架内做直线运动。当运动到框架的边界时，与框架发生弹性碰撞，弹回后继续运动。在程序运行过程中，可以调节小球运动速度的快慢，并且可以暂停。-This example is a similar game of pinball program, the program is running, the yellow ball in the white within the framework of linear motion. When the movement to the frame boundary, elastic collisions with the framework to continue the movement after the bounce. In the program is running, you can adjust the motion speed of the ball, and can be suspended.