如何检查系统是12小时还是24小时？

Question

我试图确定当前的语言环境是设置为12或24小时,并相应地设置上午/下午.这就是我现在所拥有的,但它始终显示am/pm,无论它是否设置为24.

if (DateFormat.is24HourFormat(this))
{
    mHour = mCalendar.get(Calendar.HOUR_OF_DAY);
    int hourOfDay = mHour;
    if (hourOfDay>12)
        views.setTextViewText(R.id.AMPM, "pm");
    if (hourOfDay==12)
        views.setTextViewText(R.id.AMPM, "pm");
    if (hourOfDay<12)
        views.setTextViewText(R.id.AMPM, "am");
}
else {
    views.setTextViewText(R.id.AMPM, "");           
}

Answer 1

不应该

if (!DateFormat.is24HourFormat(this))

你只想在没有设置为24小时格式的情况下分配am/pm,对吗？

这是一个更紧凑的版本:

if (!DateFormat.is24HourFormat(this)) {
    mHour = mCalendar.get(Calendar.HOUR_OF_DAY);
    int hourOfDay = mHour;
    if (hourOfDay >= 12) {
        views.setTextViewText(R.id.AMPM, "pm");
    } else {
        views.setTextViewText(R.id.AMPM, "am");
    }
} else {
    views.setTextViewText(R.id.AMPM, "");
}

Answer 2

更好的解决方案和整个代码示例

Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());

// below, the "hour" and "min" are variables,to which you want to set 
//calendar.For example you can take this values from time picker
calendar.set(Calendar.HOUR_OF_DAY, hour);
calendar.set(Calendar.MINUTE, min);            

is24HourFormat = android.text.format.DateFormat.is24HourFormat(context);

if (is24HourFormat) {
    // if system uses 24hourformat dateFormat will format the calender time according to 24hourformat. "HH" means 24hourformat
    CharSequence setTime = dateFormat.format("HH:mm", calendar);

} else {
    // if system doesnt use 24hourformat dateFormat will format the calender time according to 12hourformat. "hh" means 12hourformat and "a" will show am/pm marker
    CharSequence setTime = dateFormat.format("hh:mm a", calendar);
}

Answer 3

要始终AM/PM以 12 小时格式显示而不是像vorm/nachm德语那样显示，请使用Locale.US日期格式：

/**
 * Returns the time in a localized format. The 12-hours format is always displayed with
 * AM/PM (and not for example vorm/nachm in german).
 *
 * @param context the context
 * @return Localized time (15:24 or 3:24 PM).
 */
public static String getTime(Context context, long time) {
    if (android.text.format.DateFormat.is24HourFormat(context)) {
        return new SimpleDateFormat("HH:mm", Locale.US).format(new Date(time));

    } else {
        return new SimpleDateFormat("hh:mm a", Locale.US).format(new Date(time));
    }
}