使用service跟broadcast可以定时更新UI，这里简单复习了一下service跟broadcast的一些基本使用。

    在使用的时候需要注意对应的更新UI的那个广播需要在程序里面进行注册，因为这样可以确保onReceive方法里面回调的那个content是UI对应的activity，如此可以进行转换或许对应的ui控件进行更新。

   下面是一个简单的定时器小应用，这里直接贴代码了：

   TimeActivity :

	private TimeBroadcastReceiver receiver;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		receiver = new TimeBroadcastReceiver();
		startService(new Intent(this, TimeService.class));
		registerReceiver(receiver, new         IntentFilter(getString(R.string.time_broad_action)));
	}

	@Override
	protected void onDestroy() {
		unregisterReceiver(receiver);
		super.onDestroy();
	}
}

TimeService:

    @Override

	public void onCreate() {
		super.onCreate();
		startSyncTime();
	}

	@Override
	public IBinder onBind(Intent intent) {
		return null;
	}
	
	public void startSyncTime(){
		final SimpleDateFormat df = new SimpleDateFormat("yyyy年MM月dd日hh:mm:ss");
		Timer timer = new Timer();
		timer.schedule(new TimerTask() {
			@Override
			public void run() {
				Intent intent = new Intent(getString(R.string.time_broad_action));
				intent.putExtra("time", df.format(new Date()));
				sendBroadcast(intent);
			}
		}, 1000, 1000);
	}

  TimeBroadcastReceiver:

    @Override

	public void onReceive(Context context, Intent intent) {
		TimeServiceActivity timeAct = (TimeServiceActivity) context;
		TextView tv_time = (TextView) timeAct.findViewById(R.id.tv_time);
		tv_time.setText(intent.getExtras().getString("time"));
	}

startActivity(new Intent(Settings.ACTION_WIRELESS_SETTINGS));//进入无线网络配置界面
startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS));

FILE* mFile = fopen("xxx_file", "rb");
fseek(mFile, 0, SEEK_END);
int size = ftello(mFile);