android - 如何在设置闹钟前查看闹钟时间是否已过？

Question

我尝试了下面的方法来检查闹钟时间和当前时间(以毫秒为单位)，在大多数情况下它工作正常但是当我为例如设置闹钟时。 @4:07 p.m(即刚好过了几分钟)然后比较失败..

operation_morn = PendingIntent.getBroadcast(getBaseContext(), RQS_morn,
                intent, 0);
        Calendar calNow = Calendar.getInstance();
        long current_time = calNow.getTimeInMillis();
        // Calendar calSet = (Calendar) calNow.clone();
        // calNow.set(selected_Year, selected_Month, selected_Day);
        calNow.set(Calendar.DAY_OF_MONTH, selected_Day);
        calNow.set(Calendar.MONTH, (selected_Month - 1));
        calNow.set(Calendar.YEAR, selected_Year);
        calNow.set(Calendar.HOUR_OF_DAY, Integer.parseInt(hours));
        calNow.set(Calendar.MINUTE, Integer.parseInt(minutes));
        calNow.set(Calendar.AM_PM, Calendar.AM);



        long alarm_time_in_millis = calNow.getTimeInMillis();
        if (alarm_time_in_millis > current_time) {
            alarmManager.set(AlarmManager.RTC_WAKEUP, calNow.getTimeInMillis(),
                    operation_morn);

        }

Answer 1

问题来了

calNow.set(Calendar.HOUR_OF_DAY, Integer.parseInt(hours)); // It sets hour for 24 hours format.

应该是

calNow.set(Calendar.HOUR, Integer.parseInt(hours));

---

这是错误的，因为您正在通过 calNow.set(Calendar.AM_PM, Calendar.AM) 自行设置 AM/PM。如果您处理 24 小时格式，则仅删除此行。这将解决您的问题。

---

对于时间比较，您可以使用 Timestamp ，它有比较两次的方法。尽管您可以使用 Calender也可以比较时间。

Timestamp alramTimeStamp = new Timestamp(calNow.getTimeInMillis());
Timestamp currentTimeStamp = new Timestamp(current_time);
if (alramTimeStamp.after(currentTimeStamp)) {
    alarmManager.set(AlarmManager.RTC_WAKEUP, calNow.getTimeInMillis(),
            operation_morn);
}