第一種:使用Handler獲取

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        time= (TextView) findViewById(R.id.time);
        new TimeHandler().start();
//        getTime()//第二種方法
    }

    class TimeHandler extends Thread{
        @Override
 

        public void run() {
            super.run();
            do{
                try {
                    Thread.sleep(1000);
                    Message message=new Message();
                    message.arg1=5;
                    handler.sendMessage(message);

                }
                catch
 
 (Exception e){

                }
            }while (true);
        }
    }

    private Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
                case 1:
                    long
 
 sysTime = System.currentTimeMillis();
                    CharSequence sysTimeStr = DateFormat.format("hh:mm:ss", sysTime);
                    time.setText(sysTimeStr); //更新時間
                    break;
                default:
                   break;

            }
        }
    };

    /**
     * 第二種方式 使用Handler
     *
     */
    private Handler handlers=new Handler();

    private void getTime(){
        Timer timer=new Timer();

        TimerTask timerTask=new TimerTask() {
            @Override
            public void run() {
                SimpleDateFormat format=new SimpleDateFormat("HH:mm");
                final String times=format.format(new Date());
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        time.setText(times);

                    }
                });
            }
        };
        timer.schedule(timerTask,0,1000);
    }

第二種:使用服務

 public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        init();
        //每隔一秒傳送一次廣播
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                sendTimeChangedBroadcast();
            }
        },1000,1000);
    }

    private void init() {
        timer=new Timer();
        sdf = new SimpleDateFormat("yyyy年MM月dd日 "+"hh:mm:ss");
        timeIntent = new Intent();
        bundle = new Bundle();
    }

    /**
     * 傳送廣播，通知UI層時間已改變
     */
    private void sendTimeChangedBroadcast(){
        bundle.putString("time", getTime());
        timeIntent.putExtras(bundle);
        timeIntent.setAction(TimeServiceActivity.TIME_CHANGED_ACTION);
        //傳送廣播，通知UI層時間改變了
        sendBroadcast(timeIntent);
    }
    /**
     * 獲取最新系統時間
     * @return
     */
    private String getTime(){
        return sdf.format(new Date());
    }