事件传递

来源：互联网发布：网络作家排行榜2016 编辑：程序博客网时间：2024/05/06 19:33

    //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：

Markdown

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==148635293529502-06 11:48:55.295 10298-10298/? E/TouchEvent: ViewGroupA==onInterceptTouchEvent==false==0==148635293529502-06 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==148635286083402-06 11:47:40.835 10298-10298/? E/TouchEvent: ViewGroupA==onInterceptTouchEvent==false==0==148635286083502-06 11:47:40.835 10298-10298/? E/TouchEvent: ViewGroupB==dispatchTouchEvent==false==0==148635286083502-06 11:47:40.835 10298-10298/? E/TouchEvent: ViewGroupB==onInterceptTouchEvent==false==0==148635286083502-06 11:47:40.835 10298-10298/? E/TouchEvent: ViewGroupB==onTouchEvent==false==0==148635286083502-06 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==148635270155602-06 11:45:01.557 10298-10298/? E/TouchEvent: ViewGroupA==onInterceptTouchEvent==false==0==148635270155702-06 11:45:01.557 10298-10298/? E/TouchEvent: ViewGroupB==dispatchTouchEvent==false==0==148635270155702-06 11:45:01.557 10298-10298/? E/TouchEvent: ViewGroupB==onInterceptTouchEvent==false==0==148635270155702-06 11:45:01.557 10298-10298/? E/TouchEvent:MyView==dispatchTouchEvent==false==0==148635270155702-06 11:45:01.557 10298-10298/? E/TouchEvent: MyView==onTouchEvent==false==0==148635270155702-06 11:45:01.562 10298-10298/? E/TouchEvent:ViewGroupB==onTouchEvent==false==0==148635270156202-06 11:45:01.562 10298-10298/? E/TouchEvent: ViewGroupA==onTouchEvent==false==0==1486352701562

参考：

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