建立一个应用程序实现球与球的碰撞，球与壁的碰撞。有一个滑动面板控制球的速度，有一个滑动面板可以增加球的个数-Build an application to achieve the collision of the ball and the ball, the ball and the wall of the collision. A sliding panel to control the speed of the ball, there is a sliding panel can be in