android延時執行

使用postDelayed

new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
               //代碼塊
            }
        },long delayMillis);

定時器

        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                //代碼塊
            }
        };
        Timer timer = new Timer();
        timer.schedule(task,long delay);

開啓新線程

new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(3000);
                    //利用Handler回到主線程
                    Message message = new Message();
                    message.what = 1;
                    handler.sendMessage(message);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();

	//handler
    Handler handler = new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            if(msg.what ==1){
                tv.setText("");
            }
        }
    };