Question

android用broadcastreceiver监听网络

若网络断开则弹出对话框，提示网络断开，并让用户选择是否打开网络设置，用户选择“确定”，打开网络设置。需要源码！！！

Answer 1

采用Service+BroadcastReceiver的形式实时监听网络变化。
原理是程序在背后启一个Service，在Service中注册一个广播，当网络变化时会产生一个ConnectivityManager.CONNECTIVITY_ACTION事件，只要监听这个事件就可以了。JAVA代码如下：
import android.app.Service;
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.IBinder;
import android.util.Log;

public class NetworkStateService extends Service{

private static final String tag="tag";
private ConnectivityManager connectivityManager;
private NetworkInfo info;

private BroadcastReceiver mReceiver = new BroadcastReceiver() {

@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
Log.d(tag, "网络状态已经改变");
connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
info = connectivityManager.getActiveNetworkInfo();
if(info != null && info.isAvailable()) {
String name = info.getTypeName();
Log.d(tag, "当前网络名称：" + name);
//doSomething()
} else {
Log.d(tag, "没有可用网络");
//doSomething()
}
}
}
};

@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}

@Override
public void onCreate() {
super.onCreate();
IntentFilter mFilter = new IntentFilter();
mFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(mReceiver, mFilter);
}

@Override
public void onDestroy() {
super.onDestroy();
unregisterReceiver(mReceiver);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
return super.onStartCommand(intent, flags, startId);
}

}
别忘了在Manifast中配置这个Service：
Xml代码 收藏代码
<service android:enabled="true" android:name="com.reyo.util.NetworkStateService" />

还有权限：
Xml代码 收藏代码
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

在必要的地方启动该Service即可：
Java代码 收藏代码
Intent i=new Intent(context,NetworkStateService.class);
startService(i);

Answer 2

这个网上已经有好多demo了，给你找了2个，结合起来就行了。
http://www.cnblogs.com/sipher/articles/2567697.html
http://blog.csdn.net/wangjia55/article/details/7924664