简述
Android系统中，每个Activity的用户界面都是有View和ViewGroup对象来组成的。
那么当在界面上做了点击之后，点击事件是如何传递并处理的呢？
首先点击事件处理相关的有三个接口函数：
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//分派事件
public boolean dispatchTouchEvent(MotionEvent ev)
//拦截事件，ViewGroup类中的源码实现就是{return false;}
表示不拦截该事件，事件将向下传递（传递给其子View）；
若手动重写该方法，使其返回
true则表示拦截，事件将终止向下传递，
事件由当前ViewGroup类来处理，就是调用该类的
onTouchEvent
()方法
public
boolean
onInterceptTouchEvent
(MotionEvent ev)
//处理事件，返回true则表示该View能处理该事件，事件将
终止向上传递（传递给其父View）；返回
false表示不能处理，
则把事件传递给其父View的
onTouchEvent
()方法来处理
public
boolean
onTouchEvent
(MotionEvent event)
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只有ViewGroup才有onInterceptTouchEvent这个方法，可以向下拦截事件的传递。
示例
下面根据一个示例进行说明：TouchEventSample(代码地址)
蓝色区域为MyRelativeLayout（继承自RelativeLayout，重写了上述三个方法，用于测试点击事件拦截和处理）
白色区域为MyTextView（重写了dispatchTouchEvent和onTouchEvent两个方法）
MainActivity，则重写了上述三个方法
点击右上角case1-case5，分别对应五种情况。
case1:
点击事件，均不拦截，MyTextView也不做处理。
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E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onInterceptTouchEvent, MotionEvent.ACTION_DOWN
E/MyTextView: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyTextView: onTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MainActivity: onTouchEvent, MotionEvent.ACTION_UP
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case2:
点击事件，均不拦截，MyTextView处理点击事件。
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E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onInterceptTouchEvent, MotionEvent.ACTION_DOWN
E/MyTextView: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyTextView: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MyRelativeLayout: onInterceptTouchEvent, MotionEvent.ACTION_MOVE
E/MyTextView: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MyTextView: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MyRelativeLayout: onInterceptTouchEvent, MotionEvent.ACTION_UP
E/MyTextView: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MyTextView: onTouchEvent, MotionEvent.ACTION_UP
E/MainActivity: onTouchEvent, MotionEvent.ACTION_UP
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case3:
点击事件，MyRelativeLayout进行拦截，但不做处理。
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E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onInterceptTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MainActivity: onTouchEvent, MotionEvent.ACTION_UP
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case4:
点击事件，MyRelativeLayout进行拦截，并进行处理。
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E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onInterceptTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MyRelativeLayout: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MyRelativeLayout: onTouchEvent, MotionEvent.ACTION_UP
E/MainActivity: onTouchEvent, MotionEvent.ACTION_UP
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case5:
点击事件，均不拦截，MainActivity处理点击事件。
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E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onInterceptTouchEvent, MotionEvent.ACTION_DOWN
E/MyTextView: dispatchTouchEvent, MotionEvent.ACTION_DOWN
E/MyTextView: onTouchEvent, MotionEvent.ACTION_DOWN
E/MyRelativeLayout: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: onTouchEvent, MotionEvent.ACTION_DOWN
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: onTouchEvent, MotionEvent.ACTION_MOVE
E/MainActivity: dispatchTouchEvent, MotionEvent.ACTION_UP
E/MainActivity: onTouchEvent, MotionEvent.ACTION_UP
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参考文章：
Android-Developer-输入事件
Managing Touch Events in a ViewGroup