下面的代码可能是解决这个问题的一个好方法。它可能不是最好的，但是只要它工作，它就是好的

int timesPressed = 0;
    boolean timesUp = false;
    long millisInFuture = 5000; //ms until countdown stops
    long countDownInterval = 50; //the rate at which countdown ticks (here, once every 50 ms)
    public CountDownTimer countDownTimer = new CountDownTimer(millisInFuture, countDownInterval) {
        @Override
        public void onTick(long millisUntilFinished) {
            return;
        }
        @Override
        public void onFinish() {
            timesUp = true;
            timesPressed = 0;
        }
    };
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_VOLUME_UP){
            timesPressed++;
            countDownTimer.start();

            if (!timesUp && timesPressed == 5) { 
                countDownTimer.cancel(); //stops timer
                timesUp = false; 
                timesPressed = 0;
                doStuff(); //execute your function
            }
        }
        return true;
    }