定时器

/**
 * 輔導開始收費
 */
private void counselingStartCharging() {
    timer = new Timer(true);
    TimerTask timerTask = new TimerTask() {
        @Override
        public void run() {
            currentQ = sub(myLearnQ, teachingQ);
            myLearnQ = currentQ;
            resultQ = sub(currentQ, teachingQ);

            if (resultQ <= teachingQ) {
                EventBus.getDefault().post(new CounselingEventBus("餘額不足", "一對一輔導"));
                timer.cancel();
                //余额不足，结束辅导
                endCounseling();
            } else {
                //余额充足，开始辅导
                startCounseling();
            }
            Log.d(TAG, "run: ----------------------" + resultQ);

        }
    };
    timer.schedule(timerTask, 60 * 1000, 60 * 1000);
}

public static double sub(double d1, double d2) {
    BigDecimal b1 = new BigDecimal(Double.toString(d1));
    BigDecimal b2 = new BigDecimal(Double.toString(d2));
    return b1.subtract(b2).doubleValue();
}