android广播注册简单用法

注册广播有两种方法：动态注册（在代码中注册），静态注册（AndroiMainfest.xml）。

实现注册你需要指明：要监听什么广播，和监听之后要做什么动作（自定义广播重写onReceive）。

举一个监听网络变化的例子

要监听的广播是："android.net.conn.CONNECTIVITY_CHANGE"

收到此广播之后我们要发一个通知（Toast）

1.动态注册：

在MainActivity的onCreate()方法里修改:

package com.example.broadcasttest;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends Activity {

	private IntentFilter intentFilter;
	private NetworkChangeReceiver networkChangeReceiver;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		intentFilter = new IntentFilter();
		intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");  //添加要收到的广播
		networkChangeReceiver = new NetworkChangeReceiver();                    //广播实例
		registerReceiver(networkChangeReceiver, intentFilter);                         //注册
	}

	
	@Override
	public void onDestroy(){
		super.onDestroy();
		unregisterReceiver(networkChangeReceiver);
	}
	
	class NetworkChangeReceiver extends BroadcastReceiver{
		@Override
		public void onReceive(Context context, Intent intent){
			ConnectivityManager connectionManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
			NetworkInfo networkInfo = connectionManager.getActiveNetworkInfo();
			if(networkInfo != null && networkInfo.isAvailable()){
				Toast.makeText(context, "network is available", Toast.LENGTH_SHORT).show();
			}
			else{
				Toast.makeText(context, "network is unavailable", Toast.LENGTH_SHORT).show();
			}
			
		}
	}
}

2。静态注册：

新建一个NetworkChangeReceiver类：

public class NetworkChangeReceiver extends BroadcastReceiver{
		@Override
		public void onReceive(Context context, Intent intent){
			ConnectivityManager connectionManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
			NetworkInfo networkInfo = connectionManager.getActiveNetworkInfo();
			if(networkInfo != null && networkInfo.isAvailable()){
				Toast.makeText(context, "network is available", Toast.LENGTH_SHORT).show();
			}
			else{
				Toast.makeText(context, "network is unavailable", Toast.LENGTH_SHORT).show();
			}
			
		}
	}

然后在AndroidMainfest.xml注册这个广播：

<application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <receiver android:name=<span style="color:#33FF33;">".NetworkChangeReceiver"</span>>
            <intent-filter>
                <action android:name=<span style="color:#33CC00;">"android.net.conn.CONNECTIVITY_CHANGE"</span>/>
            </intent-filter>
           </receiver>
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

别忘了在AndroidMainfest.xml中加上查询网络状态的权限:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>