使用日历确定上午或下午日期

问题描述

| 使用日历类确定上午或下午时间。

            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AM或PM。 同样由于某些原因，Calendar.MONTH值不能提供正确的月份。一开始，这就是为什么我必须添加1。只是想知道那是否正常吗？

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

    

解决方法

        这是正常的。因为

Calendar.MONTH

的索引从0开始。因此，为什么需要

+1

才能获取正确的Month。     ,        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
}

    ,        确定AM与PM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\";
}

    ,        我试过了，但是没有用。我必须获取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
    }