Android触摸事件的分发机制

it2022-05-12 44

---恢复内容开始---

一、MotionEvent : ACTION_DOWN（下按事件）、ACTION_UP（松开事件）、ACTION_MOVE（移动事件）

二、三大函数

1.dispatchTouchEvent(Event event) == > 分发函数，由系统自动调用（返回值为true时，viewGroup可以向其子控件分发事件，view则分发给自身）

public boolean dispatchTouchEvent(MotionEvent ev) { int action = ev.getAction(); switch(action){ case MotionEvent.ACTION_DOWN: Log.e("MyLinearLayout2", "dispatchTouchEvent-->ACTION_DOWN"); break; case MotionEvent.ACTION_MOVE: Log.e("MyLinearLayout2","dispatchTouchEvent-->ACTION_MOVE"); break; case MotionEvent.ACTION_UP: Log.e("MyLinearLayout2","dispatchTouchEvent-->ACTION_UP"); break; } return super.dispatchTouchEvent(ev);

}

2.onInterceptTouchEvent(Event event) ==> 拦截函数（viewGroup有，view没有）

a.返回值为true时，viewGroup对象会将事件拦截，使得之后的UP和MOVE不会被任何控件相应;

b.返回值为false时，viewGroup不拦截事件，事件可以正常分发。

public boolean onInterceptTouchEvent(MotionEvent ev) {

int action = ev.getAction(); switch(action){ case MotionEvent.ACTION_DOWN: Log.e("MyLInearLayout","onInterceptTouchEvent-->ACTION_DOWN"); break; case MotionEvent.ACTION_MOVE: Log.e("MyLInearLayout","onInterceptTouchEvent-->ACTION_MOVE"); break; case MotionEvent.ACTION_UP: Log.e("MyLInearLayout","onInterceptTouchEvent-->ACTION_UP"); break; } return false; }

3.onTouchEvent(Event event) == >触摸相应函数

a.事件逐级向下传递，直到某个view或viewGroup执行onTouchEvent，若返回值为false，则会通知其父viewGroup执行onTouchEvent,若返回值为true，则不通知其父viewGroup执行onTouchEvent;

b.当某个view或viewGroup的onTouchEvent（）相应，并且返回值为true时，之后的MOVE和UP的响应事件都会直接传递给该空间，并由该控件的onTouchEvent()响应；

直接上代码：

MainActivity:

1 package com.example.qjm3662.myapplication; 2 3 import android.app.Activity; 4 import android.content.Context; 5 import android.os.Bundle; 6 import android.support.design.widget.FloatingActionButton; 7 import android.support.design.widget.Snackbar; 8 import android.support.v7.app.AppCompatActivity; 9 import android.support.v7.widget.Toolbar; 10 import android.util.AttributeSet; 11 import android.util.Log; 12 import android.view.MotionEvent; 13 import android.view.View; 14 import android.view.Menu; 15 import android.view.MenuItem; 16 import android.widget.LinearLayout; 17 18 public class MainActivity extends Activity{ 19 20 @Override 21 protected void onCreate(Bundle savedInstanceState) { 22 super.onCreate(savedInstanceState); 23 setContentView(R.layout.activity_main); 24 }

25 }

MyLInearLayout:

1 package com.example.qjm3662.myapplication; 2 3 import android.content.Context; 4 import android.util.AttributeSet; 5 import android.util.Log; 6 import android.view.MotionEvent; 7 import android.widget.LinearLayout; 8 9 /** 10 * Created by qjm3662 on 2016/4/10 0010. 11 */ 12 public class MyLInearLayout extends LinearLayout { 13 public MyLInearLayout(Context context, AttributeSet attrs) { 14 super(context, attrs); 15 } 16 17 @Override 18 public boolean dispatchTouchEvent(MotionEvent ev) { 19 int action = ev.getAction(); 20 switch(action){ 21 case MotionEvent.ACTION_DOWN: 22 Log.e("MyLInearLayout","dispatchTouchEvent-->ACTION_DOWN"); 23 break; 24 case MotionEvent.ACTION_MOVE: 25 Log.e("MyLInearLayout","dispatchTouchEvent-->ACTION_MOVE"); 26 break; 27 case MotionEvent.ACTION_UP: 28 Log.e("MyLInearLayout","dispatchTouchEvent-->ACTION_UP"); 29 break; 30 } 31 return super.dispatchTouchEvent(ev); 32 } 33 34 @Override 35 public boolean onTouchEvent(MotionEvent event) { 36 int action = event.getAction(); 37 switch(action){ 38 case MotionEvent.ACTION_DOWN: 39 Log.e("MyLInearLayout","onTouchEvent-->ACTION_DOWN"); 40 break; 41 case MotionEvent.ACTION_MOVE: 42 Log.e("MyLInearLayout","onTouchEvent-->ACTION_MOVE"); 43 break; 44 case MotionEvent.ACTION_UP: 45 Log.e("MyLInearLayout","onTouchEvent-->ACTION_UP"); 46 break; 47 } 48 return false; 49 } 50 51 @Override 52 public boolean onInterceptTouchEvent(MotionEvent ev) { 53 54 int action = ev.getAction(); 55 switch(action){ 56 case MotionEvent.ACTION_DOWN: 57 Log.e("MyLInearLayout","onInterceptTouchEvent-->ACTION_DOWN"); 58 break; 59 case MotionEvent.ACTION_MOVE: 60 Log.e("MyLInearLayout","onInterceptTouchEvent-->ACTION_MOVE"); 61 break; 62 case MotionEvent.ACTION_UP: 63 Log.e("MyLInearLayout","onInterceptTouchEvent-->ACTION_UP"); 64 break; 65 } 66 return false; 67 } 68

69 }

MyLinearLayout2:

1 package com.example.qjm3662.myapplication; 2 3 import android.content.Context; 4 import android.util.AttributeSet; 5 import android.util.Log; 6 import android.view.MotionEvent; 7 import android.widget.LinearLayout; 8 9 /** 10 * Created by qjm3662 on 2016/4/10 0010. 11 */ 12 public class MyLinearLayout2 extends LinearLayout{ 13 public MyLinearLayout2(Context context) { 14 super(context); 15 } 16 17 public MyLinearLayout2(Context context, AttributeSet attrs) { 18 super(context, attrs); 19 } 20 21 public MyLinearLayout2(Context context, AttributeSet attrs, int defStyleAttr) { 22 super(context, attrs, defStyleAttr); 23 } 24 25 @Override 26 public boolean dispatchTouchEvent(MotionEvent ev) { 27 int action = ev.getAction(); 28 switch(action){ 29 case MotionEvent.ACTION_DOWN: 30 Log.e("MyLinearLayout2", "dispatchTouchEvent-->ACTION_DOWN"); 31 break; 32 case MotionEvent.ACTION_MOVE: 33 Log.e("MyLinearLayout2","dispatchTouchEvent-->ACTION_MOVE"); 34 break; 35 case MotionEvent.ACTION_UP: 36 Log.e("MyLinearLayout2","dispatchTouchEvent-->ACTION_UP"); 37 break; 38 } 39 return super.dispatchTouchEvent(ev); 40 } 41 42 @Override 43 public boolean onTouchEvent(MotionEvent event) { 44 int action = event.getAction(); 45 switch(action){ 46 case MotionEvent.ACTION_DOWN: 47 Log.e("MyLinearLayout2","onTouchEvent-->ACTION_DOWN"); 48 break; 49 case MotionEvent.ACTION_MOVE: 50 Log.e("MyLinearLayout2","onTouchEvent-->ACTION_MOVE"); 51 break; 52 case MotionEvent.ACTION_UP: 53 Log.e("MyLinearLayout2","onTouchEvent-->ACTION_UP"); 54 break; 55 } 56 return false; 57 } 58 59 @Override 60 public boolean onInterceptTouchEvent(MotionEvent ev) { 61 62 int action = ev.getAction(); 63 switch(action){ 64 case MotionEvent.ACTION_DOWN: 65 Log.e("MyLinearLayout2","onInterceptTouchEvent-->ACTION_DOWN"); 66 break; 67 case MotionEvent.ACTION_MOVE: 68 Log.e("MyLinearLayout2","onInterceptTouchEvent-->ACTION_MOVE"); 69 break; 70 case MotionEvent.ACTION_UP: 71 Log.e("MyLinearLayout2","onInterceptTouchEvent-->ACTION_UP"); 72 break; 73 } 74 return true; 75 }

76 }

view:

1 package com.example.qjm3662.myapplication; 2 3 import android.content.Context; 4 import android.util.AttributeSet; 5 import android.util.Log; 6 import android.view.MotionEvent; 7 import android.widget.TextView; 8 9 /** 10 * Created by qjm3662 on 2016/4/10 0010. 11 */ 12 public class view extends TextView{ 13 14 15 public view(Context context) { 16 super(context); 17 } 18 19 public view(Context context, AttributeSet attrs) { 20 super(context, attrs); 21 } 22 23 public view(Context context, AttributeSet attrs, int defStyleAttr) { 24 super(context, attrs, defStyleAttr); 25 } 26 27 28 @Override 29 public boolean dispatchTouchEvent(MotionEvent ev) { 30 int action = ev.getAction(); 31 switch(action){ 32 case MotionEvent.ACTION_DOWN: 33 Log.e("view","dispatchTouchEvent-->ACTION_DOWN"); 34 break; 35 case MotionEvent.ACTION_MOVE: 36 Log.e("view","dispatchTouchEvent-->ACTION_MOVE"); 37 break; 38 case MotionEvent.ACTION_UP: 39 Log.e("view","dispatchTouchEvent-->ACTION_UP"); 40 break; 41 } 42 return super.dispatchTouchEvent(ev); 43 } 44 45 @Override 46 public boolean onTouchEvent(MotionEvent event) { 47 int action = event.getAction(); 48 switch(action){ 49 case MotionEvent.ACTION_DOWN: 50 Log.e("view","onTouchEvent-->ACTION_DOWN"); 51 break; 52 case MotionEvent.ACTION_MOVE: 53 Log.e("view","onTouchEvent-->ACTION_MOVE"); 54 break; 55 case MotionEvent.ACTION_UP: 56 Log.e("view","onTouchEvent-->ACTION_UP"); 57 break; 58 } 59 return true; 60 } 61 62 63 }

view2:

1 package com.example.qjm3662.myapplication; 2 3 import android.content.Context; 4 import android.util.AttributeSet; 5 import android.util.Log; 6 import android.view.MotionEvent; 7 import android.widget.ImageView; 8 9 /** 10 * Created by qjm3662 on 2016/4/10 0010. 11 */ 12 public class view2 extends ImageView{ 13 public view2(Context context) { 14 super(context); 15 } 16 17 public view2(Context context, AttributeSet attrs) { 18 super(context, attrs); 19 } 20 21 public view2(Context context, AttributeSet attrs, int defStyleAttr) { 22 super(context, attrs, defStyleAttr); 23 } 24 25 @Override 26 public boolean dispatchTouchEvent(MotionEvent event) { 27 int action = event.getAction(); 28 switch(action){ 29 case MotionEvent.ACTION_DOWN: 30 Log.e("view2", "dispatchTouchEvent-->ACTION_DOWN"); 31 break; 32 case MotionEvent.ACTION_MOVE: 33 Log.e("view2","dispatchTouchEvent-->ACTION_MOVE"); 34 break; 35 case MotionEvent.ACTION_UP: 36 Log.e("view2","dispatchTouchEvent-->ACTION_UP"); 37 break; 38 } 39 return super.dispatchTouchEvent(event); 40 } 41 42 @Override 43 public boolean onTouchEvent(MotionEvent event) { 44 int action = event.getAction(); 45 switch(action){ 46 case MotionEvent.ACTION_DOWN: 47 Log.e("view2","onTouchEvent-->ACTION_DOWN"); 48 break; 49 case MotionEvent.ACTION_MOVE: 50 Log.e("view2","onTouchEvent-->ACTION_MOVE"); 51 break; 52 case MotionEvent.ACTION_UP: 53 Log.e("view2","onTouchEvent-->ACTION_UP"); 54 break; 55 } 56 return false; 57 }

58 }

布局：

<? xml version="1.0" encoding="utf-8" ?> < com .example.qjm3662.myapplication.MyLInearLayout android:layout_width ="match_parent" android:layout_height ="match_parent" android:orientation ="vertical" xmlns:android ="http://schemas.android.com/apk/res/android" > < com .example.qjm3662.myapplication.view android:text ="dsvsdvsvsdv" android:textSize ="24sp" android:layout_width ="wrap_content" android:layout_height ="wrap_content" /> < com .example.qjm3662.myapplication.MyLinearLayout2 android:layout_width ="50dp" android:layout_height ="50dp" android:orientation ="vertical" > < com .example.qjm3662.myapplication.view2 android:src ="@drawable/ic_launcher" android:layout_width ="wrap_content" android:layout_height ="wrap_content" /> </ com.example.qjm3662.myapplication.MyLinearLayout2 >

</com.example.qjm3662.myapplication.MyLInearLayout>

运行结果：

点击上面的TextView后松开：

04-10 06:42:32.234 2414-2414/com.example.qjm3662.myapplication E/MyLInearLayout: dispatchTouchEvent-->ACTION_DOWN 04-10 06:42:32.234 2414-2414/com.example.qjm3662.myapplication E/MyLInearLayout: onInterceptTouchEvent-->ACTION_DOWN 04-10 06:42:32.234 2414-2414/com.example.qjm3662.myapplication E/view: dispatchTouchEvent-->ACTION_DOWN 04-10 06:42:32.234 2414-2414/com.example.qjm3662.myapplication E/view: onTouchEvent-->ACTION_DOWN 04-10 06:42:32.474 2414-2414/com.example.qjm3662.myapplication E/MyLInearLayout: dispatchTouchEvent-->ACTION_UP 04-10 06:42:32.474 2414-2414/com.example.qjm3662.myapplication E/MyLInearLayout: onInterceptTouchEvent-->ACTION_UP 04-10 06:42:32.474 2414-2414/com.example.qjm3662.myapplication E/view: dispatchTouchEvent-->ACTION_UP 04-10 06:42:32.474 2414-2414/com.example.qjm3662.myapplication E/view: onTouchEvent-->ACTION_UP

点击下面的ImagView后松开：

04-10 06:43:58.322 2414-2414/com.example.qjm3662.myapplication E/MyLInearLayout: dispatchTouchEvent-->ACTION_DOWN 04-10 06:43:58.322 2414-2414/com.example.qjm3662.myapplication E/MyLInearLayout: onInterceptTouchEvent-->ACTION_DOWN 04-10 06:43:58.322 2414-2414/com.example.qjm3662.myapplication E/MyLinearLayout2: dispatchTouchEvent-->ACTION_DOWN 04-10 06:43:58.322 2414-2414/com.example.qjm3662.myapplication E/MyLinearLayout2: onInterceptTouchEvent-->ACTION_DOWN 04-10 06:43:58.322 2414-2414/com.example.qjm3662.myapplication E/MyLinearLayout2: onTouchEvent-->ACTION_DOWN

04-10 06:43:58.322 2414-2414/com.example.qjm3662.myapplication E/MyLInearLayout: onTouchEvent-->ACTION_DOWN

转载于:https://www.cnblogs.com/qjm253/p/5374882.html

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