Android事件传递

来源：互联网发布：蓄水池抽样算法编辑：程序博客网时间：2024/06/05 18:08

事件传递主要有以下的调用顺序 dispatchTouchEvent --> onInterceptTouchEvent--> onTouchEvent

一、主要用到以下几个事件

（1）public boolean dispatchTouchEvent(MotionEvent ev) ：主要做事件分发的作用，源码中会调用到了onInterceptTouchEvent()和onTouchEvent() 用于去判断事件是否需要分发；

当返回值为false时则表示此事件不做分发， dispatchTouchEvent 调用完后不再走下面的onInterceptTouchEvent ，onTouchEvent ，为true时则根据 onInterceptTouchEvent ，onTouchEvent 去分发事件，走以下调用顺序：dispatchTouchEvent --> onInterceptTouchEvent--> onTouchEvent ；

（2）public boolean onInterceptTouchEvent(MotionEvent ev) ：事件拦截，主要是用于拦截事件是否向下传递，当返回为false时，则事件往下传递，当返回为true时，事件则不向下传递。（继承与ViewGroup的子类才有改方法，继承于View的之类则没有此方法）

（3） public boolean onTouchEvent(MotionEvent event) : 事件消化，如果返回为true时则事件被消化掉，不再向父传递，若果返回为false则向父view传递

二、进行如下实验，写了三个自定义事件，继承于LinearLayout ,分别都重写他的三个事件传递方法；

public class MyView2 extends LinearLayout {

    public MyView2(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        Log.d("MyView0", "MyView2 onTouchEvent eventType = " + event.getAction() + " eventX = " + event.getX() + " eventY = " + event.getY());
        return super.onTouchEvent(event);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        Log.d("MyView0","MyView2 onInterceptTouchEvent eventType = "+ev.getAction()+" eventX = "+ev.getX()+" eventY = "+ev.getY());
        return super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        Log.d("MyView0","MyView2 dispatchTouchEvent eventType = "+ev.getAction()+" eventX = "+ev.getX()+" eventY = "+ev.getY());
        return super.dispatchTouchEvent(ev);
    }
}

（1）、页面布局如下：

<?xml version="1.0" encoding="utf-8"?>
<com.prj.test.yan.eventTranslate.utils.MyView0
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:background="#ffffff"
        android:orientation="vertical">
    >
    <com.prj.test.yan.eventTranslate.utils.MyView1
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="50dp"
            android:background="#538CCC"
            android:id="@+id/myView1"
            android:orientation="vertical"
            >
        <com.prj.test.yan.eventTranslate.utils.MyView2
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_margin="50dp"
                android:background="#2CA748"
                android:id="@+id/myView2"
                android:orientation="horizontal"
                >
            <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="测试"/>
        </com.prj.test.yan.eventTranslate.utils.MyView2>
    </com.prj.test.yan.eventTranslate.utils.MyView1>
</com.prj.test.yan.eventTranslate.utils.MyView0>

（2）进行以下实验：

a、在事件分发（dispatchTouchEvent）方法中拦截：

1、MyView0 中返回false，则事件不再调用 onInterceptTouchEvent--> onTouchEvent ，点击任何部分都只拦截到了MyView0 的事件，不再往包裹的子view传递；

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        Log.d("MyView0","MyView0 dispatchTouchEvent eventType = "+ev.getAction()+" eventX = "+ev.getX()+" eventY = "+ev.getY());
          return false;
//        return super.dispatchTouchEvent(ev);

    }

结果：

07-28 15:06:27.305 11933-11933/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 75.89459 eventY = 763.2896

07-28 15:06:28.313 11933-11933/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 153.7864 eventY = 759.2927

07-28 15:06:29.073 11933-11933/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 289.59778 eventY = 752.2982

2、MyView1 返回false

07-28 15:11:25.130 13289-13289/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 152.7878 eventY = 725.3193

07-28 15:11:25.130 13289-13289/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 152.7878 eventY = 725.3193

07-28 15:11:25.130 13289-13289/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 dispatchTouchEvent eventType = 0 eventX = 52.787796 eventY = 625.3193

07-28 15:11:25.130 13289-13289/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onTouchEvent eventType = 0 eventX = 152.7878 eventY = 725.3193

b、在onInterceptTouchEvent 中拦截

1、返回为true时则事件不再往子view传递

点击MyView0 的日志：

07-28 15:19:01.544 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 36.948685 eventY = 814.2498

07-28 15:19:01.544 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 36.948685 eventY = 814.2498

07-28 15:19:01.544 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onTouchEvent eventType = 0 eventX = 36.948685 eventY = 814.2498

点击MyView1 的日志：

07-28 15:20:05.999 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 183.7448 eventY = 633.3911

07-28 15:20:05.999 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 183.7448 eventY = 633.3911

07-28 15:20:05.999 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onTouchEvent eventType = 0 eventX = 183.7448 eventY = 633.3911

点击MyView2 的日志：

07-28 15:20:26.643 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 290.5964 eventY = 655.3739

07-28 15:20:26.643 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 290.5964 eventY = 655.3739

07-28 15:20:26.643 13700-13700/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onTouchEvent eventType = 0 eventX = 290.5964 eventY = 655.3739

1、返回为false时则事件往子view传递

点击MyView0的日志：

07-28 15:23:33.009 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 33.952843 eventY = 795.26465

07-28 15:23:33.009 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 33.952843 eventY = 795.26465

07-28 15:23:33.009 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onTouchEvent eventType = 0 eventX = 33.952843 eventY = 795.26465

点击MyView1的日志：

07-28 15:23:57.900 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 158.77948 eventY = 901.1819

07-28 15:23:57.900 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 158.77948 eventY = 901.1819

07-28 15:23:57.900 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 dispatchTouchEvent eventType = 0 eventX = 58.77948 eventY = 801.1819

07-28 15:23:57.900 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 onInterceptTouchEvent eventType = 0 eventX = 58.77948 eventY = 801.1819

07-28 15:23:57.900 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 onTouchEvent eventType = 0 eventX = 58.77948 eventY = 801.1819

07-28 15:23:57.900 14150-14150/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onTouchEvent eventType = 0 eventX = 158.77948 eventY = 901.1819

c、onTouchEvent 事件消化

1、当onTouchEvent 返回值为true 时则消化掉改事件，事件不再往上的父view传递

点击MyView1

07-28 15:38:32.993 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 165.76978 eventY = 715.3271

07-28 15:38:32.993 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 165.76978 eventY = 715.3271

07-28 15:38:32.993 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 dispatchTouchEvent eventType = 0 eventX = 65.769775 eventY = 615.3271

07-28 15:38:32.993 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 onInterceptTouchEvent eventType = 0 eventX = 65.769775 eventY = 615.3271

07-28 15:38:32.993 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 onTouchEvent eventType = 0 eventX = 65.769775 eventY = 615.3271

07-28 15:38:33.133 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 1 eventX = 165.76978 eventY = 715.3271

07-28 15:38:33.133 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 dispatchTouchEvent eventType = 1 eventX = 65.769775 eventY = 615.3271

07-28 15:38:33.133 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 onTouchEvent eventType = 1 eventX = 65.769775 eventY = 615.3271

07-28 15:38:33.133 15091-15091/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 1 eventX = 165.76978 eventY = 715.3271

2、当onTouchEvent 返回值为false时则不消化掉改事件，事件往上的父view传递

点击MyView2

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 dispatchTouchEvent eventType = 0 eventX = 335.534 eventY = 554.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onInterceptTouchEvent eventType = 0 eventX = 335.534 eventY = 554.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 dispatchTouchEvent eventType = 0 eventX = 235.534 eventY = 454.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 onInterceptTouchEvent eventType = 0 eventX = 235.534 eventY = 454.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView2 dispatchTouchEvent eventType = 0 eventX = 135.534 eventY = 354.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView2 onInterceptTouchEvent eventType = 0 eventX = 135.534 eventY = 354.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView2 onTouchEvent eventType = 0 eventX = 135.534 eventY = 354.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView1 onTouchEvent eventType = 0 eventX = 235.534 eventY = 454.45276

07-28 15:45:20.928 15866-15866/com.prj.test.yan.eventTranslate D/MyView0﹕ MyView0 onTouchEvent eventType = 0 eventX = 335.534 eventY = 554.45276

总结如下：借用以下别人博文的两张图

dispatchTouchEvent ,onInterceptTouchEvent 主要用于事件的向下传递，

0 0