Android提高第六篇之BroadcastReceiver

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

 < 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：

 //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：

 <? 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：

 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：

 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();

     }
 }