Android实时监听网络状态

我们在Android应用开发中有时必须实时监听这个程序的实时网络状态，还好Android在网络断开与连接时都会发送系统广播，我们通过接收系统的广播就可以实现网络的实时监听。 

1.定义一个名为MyBroadcastReceiver的广播接收器并且实现BroadcastReceiver，重载 onReceive（）函数，并在里面对网络状态进行判断：

package com.broadcast;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class MyBroadcastReceiver extends BroadcastReceiver {

	private SharedPreferences shared = null;
	private int flag = -1;

	@Override
	public void onReceive(Context context, Intent intent) {

		// 获得网络连接服务
		ConnectivityManager connectivityManager = (ConnectivityManager) context
				.getSystemService(Context.CONNECTIVITY_SERVICE);

		// 判断是否正在使用GPRS网络
		NetworkInfo mobileNetInfo = connectivityManager
				.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

		// 判断是否正在使用WIFI网络
		NetworkInfo wifiNetInfo = connectivityManager
				.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

		if (!mobileNetInfo.isConnected() && !wifiNetInfo.isConnected()) {
			flag = 0;
		} else {
			flag = 1;
		}
		System.out.println("--当前网络状态--flag--:" + flag);
		shared = context.getSharedPreferences("UserInfo", 0);
		Editor editor = shared.edit();

		editor.putInt("network", flag);
		editor.commit();

	}
}

2.在合适的地方注册MyBroadcastReceiver，在onCreate（）中调用如下函数进行广播的注册（动态注册）：

/**
	 * 注册广播
	 */
	private void registerReceiver() {
		// 注册广播接收器
		IntentFilter filter = new IntentFilter(
				ConnectivityManager.CONNECTIVITY_ACTION);

		MyBroadcastReceiver receiver = new MyBroadcastReceiver();
		registerReceiver(receiver, filter);
	}

3.记得加权限

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