Question

我需要一个倒数计时器，就像Android的CountDownTimer一样，除了我需要它在达到零时进行注册然后继续进入底片。对此有优雅的解决方案吗？

Answer 1

我找不到一个优雅的解决方案，所以我创建了一个。如果有更好的东西存在，或者您可能做出任何改进，请告诉我：

public abstract class NegativeCountDownTimer {

private final long millisInFuture;
private final long countDownInterval;

private CountDownTimer positiveCountDownTimer;
private Timer negativeTimer;

private long zeroMillisAt;

private boolean cancelled;

public NegativeCountDownTimer(long millisInFuture, long countDownInterval) {
    this.millisInFuture = millisInFuture;
    this.countDownInterval = countDownInterval;
}

public synchronized void cancel() {
    if (positiveCountDownTimer != null) {
        positiveCountDownTimer.cancel();
    }
    if (negativeTimer != null) {
        negativeTimer.cancel();
    }
    cancelled = true;
}

public synchronized NegativeCountDownTimer start() {
    cancelled = false;
    positiveCountDownTimer = new CountDownTimer(millisInFuture, countDownInterval) {
        @Override
        public void onTick(long millisUntilFinished) {
            if (cancelled) {
                return;
            }
            onTickToc(millisUntilFinished);
        }

        @Override
        public void onFinish() {
            onZero();
            zeroMillisAt = System.currentTimeMillis();

            negativeTimer = new Timer();
            negativeTimer.scheduleAtFixedRate(new TimerTask() {
                @Override
                public void run() {
                    if (cancelled) {
                        return;
                    }
                    onTickToc(zeroMillisAt - System.currentTimeMillis());
                }
            }, 0, countDownInterval);

        }
    };
    return this;
}

public abstract void onTickToc(long millisFromFinished);

public abstract void onZero();

}

Answer 2

声明

CountDownTimer cTimer = null;
long starttime = 0L;
long timeInMilliseconds = 0L;
long timeSwapBuff = 0L;
long updatedtime = 0L;
int secs = 0;
int mins = 0;
Handler handler = new Handler();

可运行

public Runnable updateTimer = new Runnable() {
    public void run() {
        if (timeSwapBuff < 0) {
            timeInMilliseconds = SystemClock.uptimeMillis() - starttime;
            timeSwapBuff = timeSwapBuff - 1000;
            secs = (int) (timeSwapBuff / 1000);
            mins = secs / 60;
            secs = -secs % 60;
        } else {
            timeInMilliseconds = SystemClock.uptimeMillis() - starttime;
            updatedtime = timeSwapBuff + timeInMilliseconds;
            secs = (int) (updatedtime / 1000);
            mins = secs / 60;
            secs = secs % 60;
        }
        tvEta.setText((timeSwapBuff < 0 ? "" : "-") + mins + ":" + String.format("%02d", secs));
        handler.postDelayed(this, 1000);
    }
};

//start timer method
void startTimer(long time) {
    if (time < 0) {
        timeSwapBuff = TimeUnit.SECONDS.toMillis(time);
        handler.postDelayed(updateTimer, 0);
    } else {
        cTimer = new CountDownTimer(TimeUnit.SECONDS.toMillis(time), 100) {
            public void onTick(long millisUntilFinished) {
                long seconds = (millisUntilFinished / 1000) % 60;
                int minutes = (int) (millisUntilFinished / (1000 * 60));
                tvEta.setText(String.format("%d : %02d", minutes, seconds));
            }

            public void onFinish() {
                starttime = SystemClock.uptimeMillis();
                handler.postDelayed(updateTimer, 0);
            }
        };
        cTimer.start();
    }
}


//cancel timer
void cancelTimer() {
    if (cTimer != null)
        cTimer.cancel();
    handler.removeCallbacks(updateTimer);
}

CountDownTimer继续进入底片

2 个答案: