Android提高篇1 之 BroadcastReceiver 应用程序间通信的手段

BroastcastReceiver，Broastcast是应用程序间通信的手段。BroastcastReceiver也是跟Intent紧密相连的，动态/静态注册了BroastcastReceiver之后，使用sendBroadcast把Intent发送之后，系统会自动把符合条件的BroastcastReceiver启动，跟嵌入式系统的中断类似。

 

前面分别讨论了Activity和Service，这次就轮到BroastcastReceiver，Broastcast是应用程序间通信的手段。BroastcastReceiver也是跟Intent紧密相连的，动态/静态注册了BroastcastReceiver之后，使用sendBroadcast把Intent发送之后，系统会自动把符合条件的BroastcastReceiver启动，跟嵌入式系统的中断类似。

        本文主要演示了如何静态/动态注册BroastcastReceiver，向系统索取电量信息，以及枚举信息的字段。本文运行截图如下：

上图是发送Intent至内部动态注册的BroadcastReceiver，接收到之后显示消息名称。动态注册BroadcastReceiver用到registerReceiver()。

上图是发送Intent至内部静态注册的BroadcastReceiver，接收到之后显示消息名称。静态注册比动态注册麻烦点，先新建一个类继承BroadcastReceiver，然后到AndroidManifest.xml 添加

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<receiver android:name="clsReceiver2"> 
    <intent-filter> 
        <action 
            android:name="com.testBroadcastReceiver.Internal_2"/> 
    </intent-filter> 
</receiver> 
  <receiver android:name="clsReceiver2">
   <intent-filter>
    <action
     android:name="com.testBroadcastReceiver.Internal_2"/>
   </intent-filter>
  </receiver>

第一个name是类名，第二个是action的名称。

上图是枚举Intent消息的字段，这个功能比较适合懒人，把收到的Intent消息的字段全部分解了，再看看哪个需要的，懒得记住。实现这部分的代码如下：

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//当未知Intent包含的内容，则需要通过以下方法来列举  
                Bundle b=intent.getExtras();  
                Object[] lstName=b.keySet().toArray();  
 
                for(int i=0;i<lstName.length;i++)  
                {  
                    String keyName=lstName[i].toString();  
                    Log.e(keyName,String.valueOf(b.get(keyName)));  
                } 
//当未知Intent包含的内容，则需要通过以下方法来列举
    Bundle b=intent.getExtras();
    Object[] lstName=b.keySet().toArray();

    for(int i=0;i<lstName.length;i++)
    {
     String keyName=lstName[i].toString();
     Log.e(keyName,String.valueOf(b.get(keyName)));
    }

main.xml的代码如下：

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<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="fill_parent" 
    android:layout_height="fill_parent"> 
 
    <Button android:id="@+id/Button01" android:layout_width="wrap_content" 
        android:layout_height="wrap_content" android:text="发送至内部动态注册的BroadcastReceiver"></Button> 
    <Button android:id="@+id/Button02" android:layout_width="wrap_content" 
        android:layout_height="wrap_content" android:text="发送至内部静态注册BroadcastReceiver"></Button> 
    <Button android:id="@+id/Button03" android:layout_width="wrap_content" 
        android:layout_height="wrap_content" android:text="发送至系统BroadcastReceiver"></Button> 
</LinearLayout> 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical" android:layout_width="fill_parent"
 android:layout_height="fill_parent">

 <Button android:id="@+id/Button01" android:layout_width="wrap_content"
  android:layout_height="wrap_content" android:text="发送至内部动态注册的BroadcastReceiver"></Button>
 <Button android:id="@+id/Button02" android:layout_width="wrap_content"
  android:layout_height="wrap_content" android:text="发送至内部静态注册BroadcastReceiver"></Button>
 <Button android:id="@+id/Button03" android:layout_width="wrap_content"
  android:layout_height="wrap_content" android:text="发送至系统BroadcastReceiver"></Button>
</LinearLayout>
 

testBroadcastReceiver.java的代码如下：

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package com.testBroadcastReceiver;  
 
import android.app.Activity;  
import android.content.BroadcastReceiver;  
import android.content.Context;  
import android.content.Intent;  
import android.content.IntentFilter;  
import android.os.Bundle;  
import android.util.Log;  
import android.view.View;  
import android.widget.Button;  
import android.widget.Toast;  
 
public class testBroadcastReceiver extends Activity {  
    Button btnInternal1,btnInternal2,btnSystem;  
    static final String INTENAL_ACTION_1 = "com.testBroadcastReceiver.Internal_1";  
    static final String INTENAL_ACTION_2 = "com.testBroadcastReceiver.Internal_2";  
    static final String INTENAL_ACTION_3 = "com.testBroadcastReceiver.Internal_3";  
    @Override 
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
        btnInternal1=(Button)this.findViewById(R.id.Button01);  
        btnInternal1.setOnClickListener(new ClickEvent());  
        btnInternal2=(Button)this.findViewById(R.id.Button02);  
        btnInternal2.setOnClickListener(new ClickEvent());  
        btnSystem=(Button)this.findViewById(R.id.Button03);  
        btnSystem.setOnClickListener(new ClickEvent());  
        //动态注册广播消息  
        registerReceiver(bcrIntenal1, new IntentFilter(INTENAL_ACTION_1));  
    }  
    class ClickEvent implements View.OnClickListener{  
 
        @Override 
        public void onClick(View v) {  
            if(v==btnInternal1)//给动态注册的BroadcastReceiver发送数据  
            {  
                Intent intent = new Intent(INTENAL_ACTION_1);  
                sendBroadcast(intent);  
            }  
            else if(v==btnInternal2)//给静态注册的BroadcastReceiver发送数据  
            {  
                Intent intent = new Intent(INTENAL_ACTION_2);  
                sendBroadcast(intent);  
            }  
            else if(v==btnSystem)//动态注册 接收2组信息的BroadcastReceiver  
            {  
                IntentFilter filter = new IntentFilter();//  
                filter.addAction(Intent.ACTION_BATTERY_CHANGED);//系统电量检测信息  
                filter.addAction(INTENAL_ACTION_3);//第三组自定义消息  
                registerReceiver(batInfoReceiver, filter);  
                  
                Intent intent = new Intent(INTENAL_ACTION_3);  
                intent.putExtra("Name", "hellogv");  
                intent.putExtra("Blog", "http://blog.csdn.net/hellogv");  
                sendBroadcast(intent);//传递过去  
            }  
        }  
          
    }  
      
    /* 
     * 接收动态注册广播的BroadcastReceiver 
     */ 
    private BroadcastReceiver bcrIntenal1 = new BroadcastReceiver() {  
          
        public void onReceive(Context context, Intent intent) {  
            String action = intent.getAction();  
            Toast.makeText(context, "动态:"+action, 1000).show();  
        }  
    };  
      
 
    private BroadcastReceiver batInfoReceiver = new BroadcastReceiver() {  
          
        public void onReceive(Context context, Intent intent) {  
            String action = intent.getAction();  
            //如果捕捉到的action是ACTION_BATTERY_CHANGED  
            if (Intent.ACTION_BATTERY_CHANGED.equals(action)) {  
                //当未知Intent包含的内容，则需要通过以下方法来列举  
                Bundle b=intent.getExtras();  
                Object[] lstName=b.keySet().toArray();  
 
                for(int i=0;i<lstName.length;i++)  
                {  
                    String keyName=lstName[i].toString();  
                    Log.e(keyName,String.valueOf(b.get(keyName)));  
                }  
            }  
            //如果捕捉到的action是INTENAL_ACTION_3  
            if (INTENAL_ACTION_3.equals(action)) {  
                //当未知Intent包含的内容，则需要通过以下方法来列举  
                Bundle b=intent.getExtras();  
                Object[] lstName=b.keySet().toArray();  
 
                for(int i=0;i<lstName.length;i++)  
                {  
                    String keyName=lstName[i].toString();  
                    Log.e(keyName,b.getString(keyName));  
                }  
            }  
        }  
    };  
 
 
} 
package com.testBroadcastReceiver;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class testBroadcastReceiver extends Activity {
    Button btnInternal1,btnInternal2,btnSystem;
    static final String INTENAL_ACTION_1 = "com.testBroadcastReceiver.Internal_1";
    static final String INTENAL_ACTION_2 = "com.testBroadcastReceiver.Internal_2";
    static final String INTENAL_ACTION_3 = "com.testBroadcastReceiver.Internal_3";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btnInternal1=(Button)this.findViewById(R.id.Button01);
        btnInternal1.setOnClickListener(new ClickEvent());
        btnInternal2=(Button)this.findViewById(R.id.Button02);
        btnInternal2.setOnClickListener(new ClickEvent());
        btnSystem=(Button)this.findViewById(R.id.Button03);
        btnSystem.setOnClickListener(new ClickEvent());
        //动态注册广播消息
  registerReceiver(bcrIntenal1, new IntentFilter(INTENAL_ACTION_1));
    }
    class ClickEvent implements View.OnClickListener{

  @Override
  public void onClick(View v) {
   if(v==btnInternal1)//给动态注册的BroadcastReceiver发送数据
   {
    Intent intent = new Intent(INTENAL_ACTION_1);
    sendBroadcast(intent);
   }
   else if(v==btnInternal2)//给静态注册的BroadcastReceiver发送数据
   {
    Intent intent = new Intent(INTENAL_ACTION_2);
    sendBroadcast(intent);
   }
   else if(v==btnSystem)//动态注册 接收2组信息的BroadcastReceiver
   {
    IntentFilter filter = new IntentFilter();//
          filter.addAction(Intent.ACTION_BATTERY_CHANGED);//系统电量检测信息
          filter.addAction(INTENAL_ACTION_3);//第三组自定义消息
    registerReceiver(batInfoReceiver, filter);
    
    Intent intent = new Intent(INTENAL_ACTION_3);
    intent.putExtra("Name", "hellogv");
    intent.putExtra("Blog", "http://blog.csdn.net/hellogv");
    sendBroadcast(intent);//传递过去
   }
  }
     
    }
   
    /*
     * 接收动态注册广播的BroadcastReceiver
     */
 private BroadcastReceiver bcrIntenal1 = new BroadcastReceiver() {
  
  public void onReceive(Context context, Intent intent) {
   String action = intent.getAction();
   Toast.makeText(context, "动态:"+action, 1000).show();
  }
 };
 

 private BroadcastReceiver batInfoReceiver = new BroadcastReceiver() {
  
  public void onReceive(Context context, Intent intent) {
   String action = intent.getAction();
   //如果捕捉到的action是ACTION_BATTERY_CHANGED
   if (Intent.ACTION_BATTERY_CHANGED.equals(action)) {
    //当未知Intent包含的内容，则需要通过以下方法来列举
    Bundle b=intent.getExtras();
    Object[] lstName=b.keySet().toArray();

    for(int i=0;i<lstName.length;i++)
    {
     String keyName=lstName[i].toString();
     Log.e(keyName,String.valueOf(b.get(keyName)));
    }
   }
   //如果捕捉到的action是INTENAL_ACTION_3
   if (INTENAL_ACTION_3.equals(action)) {
    //当未知Intent包含的内容，则需要通过以下方法来列举
    Bundle b=intent.getExtras();
    Object[] lstName=b.keySet().toArray();

    for(int i=0;i<lstName.length;i++)
    {
     String keyName=lstName[i].toString();
     Log.e(keyName,b.getString(keyName));
    }
   }
  }
 };

}

clsReceiver2.java的代码如下：

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package com.testBroadcastReceiver;  
 
import android.content.BroadcastReceiver;  
import android.content.Context;  
import android.content.Intent;  
import android.widget.Toast;  
 
/* 
 * 接收静态注册广播的BroadcastReceiver， 
 * step1:要到AndroidManifest.xml这里注册消息 
 *      <receiver android:name="clsReceiver2"> 
            <intent-filter> 
                <action 
                    android:name="com.testBroadcastReceiver.Internal_2"/> 
            </intent-filter> 
        </receiver> 
    step2:定义消息的字符串 
    step3:通过Intent传递消息来驱使BroadcastReceiver触发 
 */ 
public class clsReceiver2 extends BroadcastReceiver{  
    @Override 
    public void onReceive(Context context, Intent intent) {  
        String action = intent.getAction();  
        Toast.makeText(context, "静态:"+action, 1000).show();  
          
    }  
} 

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/hellogv/archive/2010/11/10/5999170.aspx