在touchesBegan，touchesMoved和touchesEnded方法中，一个参数是event，它是一个UIEvent对象。屏幕上的手指数是[[event allTouches] count]。

In the touchesBegan, touchesMoved, and touchesEnded methods, one parameter is event, which is a UIEvent object. The number of fingers on the screen is [[event allTouches]count].

将无效。]