强强学Android_Android事件传递

 1  1 package org.crazyit.event;
 2  2 import android.app.Activity;
 3  3 import android.os.Bundle;
 4  4 import android.view.View;
 5  5 import android.view.View.OnClickListener;
 6  6 import android.widget.Button;
 7  7 import android.widget.EditText;
 8  8 // 实现事件监听器接口
 9  9 public class ActivityListener extends Activity
10 10     implements OnClickListener
11 11 {
12 12     EditText show;
13 13     Button bn;
14 14     @Override
15 15     public void onCreate(Bundle savedInstanceState)
16 16     {
17 17         super.onCreate(savedInstanceState);
18 18         setContentView(R.layout.main);
19 19         show = (EditText) findViewById(R.id.show);
20 20         bn = (Button) findViewById(R.id.bn);
21 21         // 直接使用Activity作为事件监听器
22 22         bn.setOnClickListener(this);
23 23     }
24 24     // 实现事件处理方法
25 25     @Override
26 26     public void onClick(View v)
27 27     {
28 28         show.setText("bn按钮被单击了！");
29 29     }
30 30 }

 1  1 <?xml version="1.0" encoding="utf-8"?>
 2  2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3  3     android:orientation="vertical"
 4  4     android:layout_width="fill_parent"
 5  5     android:layout_height="fill_parent"
 6  6     android:gravity="center_horizontal"
 7  7     >
 8  8 <EditText 
 9  9     android:id="@+id/show"
10 10     android:layout_width="fill_parent" 
11 11     android:layout_height="wrap_content" 
12 12     android:editable="false"
13 13     />
14 14 <Button 
15 15     android:id="@+id/bn"
16 16     android:layout_width="wrap_content" 
17 17     android:layout_height="wrap_content" 
18 18     android:text="单击我"
19 19     />
20 20 </LinearLayout>

 1 public class MyButton extends Button
 2 {
 3     public MyButton(Context context , AttributeSet set)
 4     {
 5         super(context , set);
 6     }
 7     @Override
 8     public boolean onKeyDown(int keyCode, KeyEvent event)
 9     {
10         super.onKeyDown(keyCode , event);
11         Log.v("-MyButton-" , "the onKeyDown in MyButton");
12         // 返回false，表明并未完全处理该事件，该事件依然向外扩散
13         return false;
14     }
15 }

 1 public class Propagation extends Activity
 2 {
 3     @Override
 4     public void onCreate(Bundle savedInstanceState)
 5     {
 6         super.onCreate(savedInstanceState);
 7         setContentView(R.layout.main);
 8         Button bn = (Button) findViewById(R.id.bn);
 9         // 为bn绑定事件监听器
10         bn.setOnKeyListener(new OnKeyListener()
11         {
12             @Override
13             public boolean onKey(View source
14                     , int keyCode, KeyEvent event)
15             {
16                 // 只处理按下键的事件
17                 if (event.getAction() == KeyEvent.ACTION_DOWN)
18                 {
19                     Log.v("-Listener-", "the onKeyDown in Listener");
20                 }
21                 // 返回false，表明该事件会向外传播
22                 return false; // (1)
23             }
24         });
25     }
26     // 重写onKeyDown方法，该方法可监听它所包含的所有组件的按键被按下事件
27     @Override
28     public boolean onKeyDown(int keyCode, KeyEvent event)
29     {
30         super.onKeyDown(keyCode , event);
31         Log.v("-Activity-" , "the onKeyDown in Activity");
32         //返回false，表明并未完全处理该事件，该事件依然向外扩散
33         return false;
34     }
35 }