事件传递

//ViewGroup的事件处理
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
boolean consume = false;

if (onInterceptTouchEvent(event)) {//ViewGroup拦截（viewgroup默认不拦截）
consume = onTouchEvent(event);//则ViewGroup处理事件
} else {//ViewGroup不拦截
consume = child.dispatchTouchEvent(event);//则子view派发事件
}

return consume;
}

事件的传递：隧道式派发

先执行dispatchTouchEvent方法

再执行onInterceptTouchEvent方法（view无此方法）

true，拦截，不用派发给下级

false，不拦截，派发给下级

事件的处理：冒泡式消费

只执行onTouchEvent方法（view没有拦截方法，事件传递过来时一定会执行这个方法，当clickable和longclickable都为true时如button默认消费事件）

true，处理了，不用处理了

false，没处理，给上级处理

dispatchTouchEvent方法：事件传递到当前view，此方法一定会被调用，返回值受当前view的onTouchEvent和下级view的dispatchTouchEvent返回值影响。

最后一级view一定会调用onTouchEvent方法。

例子如下：

MyView

public class MyView extends View {

//处理事件
@Override
public boolean onTouchEvent(MotionEvent event) {
Log.e("TouchEvent","MyView==onTouchEvent=="+super.onTouchEvent(event)+"=="
+event.getAction()+"=="+System.currentTimeMillis());
return super.onTouchEvent(event);
}

//派发事件
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
Log.e("TouchEvent","MyView==dispatchTouchEvent=="+super.onTouchEvent(ev)+"=="
+ev.getAction()+"=="+System.currentTimeMillis());
return super.dispatchTouchEvent(ev);
}

public MyView(Context context) {
super(context);
}

public MyView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
}

}

ViewGroupA

public class ViewGroupA extends LinearLayout {

//处理事件
@Override
public boolean onTouchEvent(MotionEvent event) {
Log.e("TouchEvent","ViewGroupA==onTouchEvent=="+super.onTouchEvent(event)+"=="
+event.getAction()+"=="+System.currentTimeMillis());
return super.onTouchEvent(event);
}

//派发事件
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
Log.e("TouchEvent","ViewGroupA==dispatchTouchEvent=="+super.onTouchEvent(ev)+"=="
+ev.getAction()+"=="+System.currentTimeMillis());
return super.dispatchTouchEvent(ev);
}

//拦截事件
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
Log.e("TouchEvent","ViewGroupA==onInterceptTouchEvent=="+super.onTouchEvent(ev)+"=="
+ev.getAction()+"=="+System.currentTimeMillis());
return super.onInterceptTouchEvent(ev);
}

//构造方法
public ViewGroupA(Context context) {
super(context);
}

public ViewGroupA(Context context, AttributeSet attrs) {
super(context, attrs);
}

public ViewGroupA(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

}

ViewGroupB

public class ViewGroupB extends LinearLayout {

//处理事件
@Override
public boolean onTouchEvent(MotionEvent event) {
Log.e("TouchEvent","ViewGroupB==onTouchEvent=="+super.onTouchEvent(event)+"=="
+event.getAction()+"=="+System.currentTimeMillis());
return super.onTouchEvent(event);
}

//派发事件
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
Log.e("TouchEvent","ViewGroupB==dispatchTouchEvent=="+super.onTouchEvent(ev)+"=="
+ev.getAction()+"=="+System.currentTimeMillis());
return super.dispatchTouchEvent(ev);
}

//拦截事件
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
Log.e("TouchEvent","ViewGroupB==onInterceptTouchEvent=="+super.onTouchEvent(ev)+"=="
+ev.getAction()+"=="+System.currentTimeMillis());
return super.onInterceptTouchEvent(ev);
}

public ViewGroupB(Context context) {
super(context);
}

public ViewGroupB(Context context, AttributeSet attrs) {
super(context, attrs);
}

public ViewGroupB(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

}

布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.administrator.myapplication.MainActivity">

<com.example.administrator.myapplication.ViewGroupA
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/holo_blue_bright">

<com.example.administrator.myapplication.ViewGroupB
android:layout_width="300dp"
android:layout_height="300dp"
android:background="@android:color/holo_green_dark">

<com.example.administrator.myapplication.MyView
android:layout_width="150dp"
android:layout_height="150dp"
android:background="@android:color/darker_gray" />
</com.example.administrator.myapplication.ViewGroupB>
</com.example.administrator.myapplication.ViewGroupA>

</RelativeLayout>

点击ViewGroupA

02-06 11:48:55.295 10298-10298/? E/TouchEvent:
ViewGroupA==dispatchTouchEvent==false==0==1486352935295
02-06 11:48:55.295 10298-10298/? E/TouchEvent:
ViewGroupA==onInterceptTouchEvent==false==0==1486352935295
02-06 11:48:55.295 10298-10298/? E/TouchEvent:
ViewGroupA==onTouchEvent==false==0==1486352935295

点击ViewGroupB

02-06 11:47:40.835 10298-10298/? E/TouchEvent:
ViewGroupA==dispatchTouchEvent==false==0==1486352860834
02-06 11:47:40.835 10298-10298/? E/TouchEvent:
ViewGroupA==onInterceptTouchEvent==false==0==1486352860835

02-06 11:47:40.835 10298-10298/? E/TouchEvent:
ViewGroupB==dispatchTouchEvent==false==0==1486352860835
02-06 11:47:40.835 10298-10298/? E/TouchEvent:
ViewGroupB==onInterceptTouchEvent==false==0==1486352860835
02-06 11:47:40.835 10298-10298/? E/TouchEvent:
ViewGroupB==onTouchEvent==false==0==1486352860835

02-06 11:47:40.835 10298-10298/? E/TouchEvent:
ViewGroupA==onTouchEvent==false==0==1486352860835

点击MyView

02-06 11:45:01.557 10298-10298/? E/TouchEvent:
ViewGroupA==dispatchTouchEvent==false==0==1486352701556
02-06 11:45:01.557 10298-10298/? E/TouchEvent:
ViewGroupA==onInterceptTouchEvent==false==0==1486352701557

02-06 11:45:01.557 10298-10298/? E/TouchEvent:
ViewGroupB==dispatchTouchEvent==false==0==1486352701557
02-06 11:45:01.557 10298-10298/? E/TouchEvent:
ViewGroupB==onInterceptTouchEvent==false==0==1486352701557

02-06 11:45:01.557 10298-10298/? E/TouchEvent:
MyView==dispatchTouchEvent==false==0==1486352701557
02-06 11:45:01.557 10298-10298/? E/TouchEvent:
MyView==onTouchEvent==false==0==1486352701557

02-06 11:45:01.562 10298-10298/? E/TouchEvent:
ViewGroupB==onTouchEvent==false==0==1486352701562

02-06 11:45:01.562 10298-10298/? E/TouchEvent:
ViewGroupA==onTouchEvent==false==0==1486352701562

参考：

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