使用日历确定上午或下午日期

Question

使用日历类确定 AM 或 PM 时间。

            Calendar c = Calendar.getInstance(); 
            int seconds = c.get(Calendar.SECOND);
            int minutes = c.get(Calendar.MINUTE);
            int hours = c.get(Calendar.HOUR);
            int years = c.get(Calendar.YEAR);
            int months = 1 + c.get(Calendar.MONTH);
            int days = c.get(Calendar.DAY_OF_MONTH);
            int AM_orPM = c.get(Calendar.AM_PM);

            try{
                if (hours < 12)
                {
                    String PM = "";
                    if (AM_orPM == 1)
                    {
                        PM = "PM";
                    }
                    timestamp.setText("Refreshed on " + months + "-"
                    + days + "-" + years + " " +  hours + ":" + minutes + ":" + seconds + " " + PM);
                    timestamp.setTextSize(17f);
                    timestamp.setTextColor(Color.GREEN);
                }
                else if (hours > 12)
                {
                    String AM = "";
                    if (AM_orPM == 0)
                    {
                        AM = "AM";
                    }
                    hours = hours - 12;
                    timestamp.setText("Refreshed on " + years + "-"
                    + months + "-" + days + " " +  hours + ":" + minutes + ":" + seconds + AM);
                    timestamp.setTextSize(17f);
                    timestamp.setTextColor(Color.GREEN);
                }
            }
            catch (Exception e){} 

我想根据当前时间将时间设置为上午或下午。 另外由于某种原因，Calendar.MONTH 值没有给我正确的月份。差了 1，所以我必须加 1。只是想知道这是否正常？

int months = 1 + c.get(Calendar.MONTH);

Answer 1

这是正常的。因为 Calendar.MONTH 的索引从 0 开始。所以这就是为什么你需要 +1 才能获得正确的月份。

Answer 2

只需检查calendar.get(Calendar.AM_PM) == Calendar.AM

Calendar now = Calendar.getInstance();
if(now.get(Calendar.AM_PM) == Calendar.AM){
   // AM
}else{
   // PM
}

Answer 3

确定上午与下午是基于小时的简单计算。这是代码：

String timeString="";
int hour = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
if (hour == 0) {
    timeString =  "12AM (Midnight)";  
} else if (hour < 12) {
    timeString = hour +"AM";
} else if (hour == 12) {
    timeString = "12PM (Noon)";
} else {
    timeString = hour-12 +"PM";
}

Answer 4

我尝试了这个，但它不起作用。我必须获得 AM_PM 值，然后进行比较：

int AM_PM = c.get(Calendar.AM_PM);
if(AM_PM == Calendar.AM){
...
...

这是解决方案：

   Calendar c = Calendar.getInstance();
    int AM_PM = c.get(Calendar.AM_PM);

    if(AM_PM == Calendar.AM){
       //AM
    }else{
       //PM
    }