监听手机网络状态变化

 private BroadcastReceiver mReceiver = new BroadcastReceiver() {        @Override        public void onReceive(Context context, Intent intent) {            String action = intent.getAction();            if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {                connectivityManager = (ConnectivityManager)                        getSystemService(Context.CONNECTIVITY_SERVICE);                info = connectivityManager.getActiveNetworkInfo();                if (info != null && info.isAvailable()) {                    //网络可用时，执行的代码                    return;                }                //网络不可用时，执行的代码                  }        }    };

注册接受网络状态改变接收器

 IntentFilter mFilter = new IntentFilter(); mFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION); registerReceiver(mReceiver, mFilter);

Manifest加上权限

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