Android增高第六篇之BroadcastReceiver[转]

Android提高第六篇之BroadcastReceiver[转]

? ? ? ?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：

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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()。

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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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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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<?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>

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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));                  }              }          }      };      }

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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();                }  }

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本文来自http://blog.csdn.net/hellogv/article/details/5999170

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