android 使用brocastReceiver监听网络连接状态

public class BroadcastService extends Service{

    private ConnectivityManager connectivityManager;//网络连接管理器
    private NetworkInfo networkInfo;//当前网络的信息
    //点击查看
    private PendingIntent messagePendingIntent = null;

    //通知栏消息
    private Notification messageNotification = null;
    private NotificationManager messageNotificatioManager = null;
    private Intent notificationIntent=null;
    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }
    /**
     * 定义一个broadcastReceiver
     */
    private BroadcastReceiver myReceiver=new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            // TODO Auto-generated method stub
            String action=intent.getAction();
            if(action.equals(ConnectivityManager.CONNECTIVITY_ACTION)){
                connectivityManager=(ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
                WifiManager wifiManager=(WifiManager)context.getSystemService(Context.WIFI_SERVICE);
                wifiManager.setWifiEnabled(true);
                wifiManager.startScan();//开始扫描
                List<ScanResult> listResults=wifiManager.getScanResults();
                //listResults.get(0).toString();
                networkInfo=connectivityManager.getActiveNetworkInfo();
                if(networkInfo!=null&&networkInfo.isAvailable()){
                    Log.d("netWorkInfo","当前网络连接："+networkInfo.getTypeName());
                }
                else {
                    Log.d("netWorkInfo","当前没有网络连接");
                }

            }
        }
    };

    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        IntentFilter filter=new IntentFilter();//过滤intent
        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);//添加action
        registerReceiver(myReceiver, filter);//注册receiver
        Log.i("tag","onCreate");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // TODO Auto-generated method stub
        Log.i("tag","onStartCommand");
        setNotification("新通知");
        /*int intGetTastCounter=30;

        ActivityManager mActivityManager = (ActivityManager)getSystemService(ACTIVITY_SERVICE);
        ArrayList<String> arylistTask = new ArrayList<String>();
        List<ActivityManager.RunningTaskInfo> mRunningTasks = mActivityManager.getRunningTasks(intGetTastCounter);

        int i = 0;
         以循环及baseActivity方式取得工作名称与ID
        for (ActivityManager.RunningTaskInfo amTask : mRunningTasks)
        {
                     baseActivity.getClassName取出运行工作名称
                    arylistTask.add("" + (i++) + ": "+
                    amTask.baseActivity.getClassName()+
                    "(ID=" + amTask.id +")");
                    Log.d("task", arylistTask.get(i-1));
        }*/
        return super.onStartCommand(intent, flags, startId);
    }
    /**
     * 设置通知消息
     * @param message消息类型
     */
    private void setNotification(String message){
        notificationIntent = new Intent(this, SecondActivity.class);
        messagePendingIntent = PendingIntent.getActivity(this, 0,notificationIntent,0);
        messageNotificatioManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        messageNotification=new Notification(R.drawable.ic_launcher, message, System.currentTimeMillis());
        //messageNotification.contentIntent=messagePendingIntent;
        messageNotification.setLatestEventInfo(this, message, "dfdf", messagePendingIntent);
        // 显示通知
       messageNotificatioManager.notify("df",R.drawable.ic_launcher, messageNotification);
    }
    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub

        System.out.println("关闭服务了");
        unregisterReceiver(myReceiver);//移除注册的receiver
        System.exit(0);
        super.onDestroy();
    }

}