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

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：

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{@Overridepublic 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_CHANGEDif (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_3if (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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1. package?com.testBroadcastReceiver;????
2. import?android.content.BroadcastReceiver;??import?android.content.Context;??
3. import?android.content.Intent;??import?android.widget.Toast;??
4. ??/*?
5. ?*?接收静态注册广播的BroadcastReceiver，??*?step1:要到AndroidManifest.xml这里注册消息?
6. ?*??????<receiver?android:name="clsReceiver2">?????????????<intent-filter>?
7. ????????????????<action?????????????????????android:name="com.testBroadcastReceiver.Internal_2"/>?
8. ????????????</intent-filter>?????????</receiver>?
9. ????step2:定义消息的字符串?????step3:通过Intent传递消息来驱使BroadcastReceiver触发?
10. ?*/??public?class?clsReceiver2?extends?BroadcastReceiver{??
11. ????@Override??????public?void?onReceive(Context?context,?Intent?intent)?{??
12. ????????String?action?=?intent.getAction();??????????Toast.makeText(context,?"静态:"+action,?1000).show();??
13. ??????????????}??
14. }?