a b c d e f g h i j k l m n o p q r s t u v w x y z

Android中BroadCastReceiver使用(整理)

BroadcastReceiver

  在Android中,Broadcast是一种广泛运用的在应用程序之间传输信息的机制。而BroadcastReceiver是对发送出来的 Broadcast进行过滤接受并响应的一类组件。

下面将详细的阐述如何发送Broadcast和使用BroadcastReceiver过滤接收的过程:

  首先在需要发送信息的地方,把要发送的信息和用于过滤的信息(如Action、Category)装入一个Intent对象,然后通过调用 sendOrderBroadcast()或sendStickyBroadcast()方法,把 Intent对象以广播方式发送出去。

  当Intent发送以后,所有已经注册的BroadcastReceiver会检查注册时的IntentFilter是否与发送的Intent相匹配,若匹配则就会调用BroadcastReceiver的onReceive()方法。所以当我们定义一个BroadcastReceiver的时候,都需要实现onReceive()方法。

  注册BroadcastReceiver有两种方式:

  静态注册:在AndroidManifest.xml中用标签生命注册,并在标签内用标签设置过滤器。

  <receiver android:name="myRecevice">    //继承BroadcastReceiver,重写onReceiver方法

    <intent-filter>    

      <action android:name="com.dragon.net"></action> //使用过滤器,接收指定action广播

      </intent-filter>

  </receiver> 

  动态注册:

  IntentFilter intentFilter = new IntentFilter();

  intentFilter.addAction(String);   //为BroadcastReceiver指定action,使之用于接收同action的广播

      registerReceiver(BroadcastReceiver,intentFilter);

  一般:在onStart中注册,onStop中取消unregisterReceiver

  指定广播目标Action:Intent intent = new Intent(actionString);

  并且可通过Intent携带消息 :intent.putExtra("msg", "hi,我通过广播发送消息了");

  发送广播消息:Context.sendBroadcast(intent )

 

其中在动态注册中可将BroadcastReceiver的继承类进行封装,添加构造函数和BroadcastReceiver注册

 

代码
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;

public class BroadcastReceiverHelper extends BroadcastReceiver {

NotificationManager mn
=null;
Notification notification
=null;
Context ct
=null;
BroadcastReceiverHelper receiver;

public BroadcastReceiverHelper(Context c){
ct
=c;
receiver
=this;
}

//注册
public void registerAction(String action){
IntentFilter filter
=new IntentFilter();
filter.addAction(action);
ct.registerReceiver(receiver, filter);
}

@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
String msg=intent.getStringExtra("msg");
int id=intent.getIntExtra("who", 0);
if(intent.getAction().equals("com.cbin.sendMsg")){
mn
=(NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
notification
=new Notification(R.drawable.icon, id+"发送广播", System.currentTimeMillis());
Intent it
= new Intent(context,Main.class);
PendingIntent contentIntent
=PendingIntent.getActivity(context,
0, it, 0);
notification.setLatestEventInfo(context,
"msg", msg, contentIntent);
mn.notify(
0, notification);
}
}
}

 

然后再Activity中声明BroadcastReceiver的扩展对象,在onStart中注册,onStop中卸载

 

代码

BroadcastReceiverHelper rhelper;
@Override
public void onStart(){
//注册广播接收器
rhelper=new BroadcastReceiverHelper(this);
rhelper.registerAction(
"com.cbin.sendMsg");
super.onStart();
}

@Override
public void onStop(){
//取消广播接收器
unregisterReceiver(rhelper);
super.onStop();
}

 

 

 

posted @ 2010-09-29 12:17 莴笋炒肉 阅读(...) 评论(...)  编辑 收藏