c# - 如何减去两个日期导致几天或几周？

Question

我正在寻找可以输入 2 个日期的函数:

这样开始:

         public static String getDaysOrWeeksFromDateDiff(DateTime first, DateTime second)
        {
    //this function will substract the date from the other and result days if < 8 and weeks if > 7

return "1 week";
        }

我在下面尝试过这个函数，但它给了我一个负数的日期(我在计算中不知何故错过了年份)

 public static String getDaysOrWeeksFromDateDiff(DateTime first, DateTime second)
    {
        var cal = new GregorianCalendar(GregorianCalendarTypes.Localized);
        var weeknr = cal.GetWeekOfYear(first, CalendarWeekRule.FirstDay, DayOfWeek.Monday);
        var weeknr2 = cal.GetWeekOfYear(second, CalendarWeekRule.FirstDay, DayOfWeek.Monday);
        String strReturnValue;
        if (weeknr == weeknr2)
        {
            var dagen = first.Day - second.Day;
            strReturnValue = (dagen == 0 ? "today" : (dagen == 1 ? "1 day" : dagen + " days"));
        }
        else
        {
            strReturnValue = (weeknr - weeknr2 == 1 ? "1 week" : weeknr - weeknr2 + " weeks");
        }
        return strReturnValue;
    }

Answer 1

您可以 subtract dates directly :

TimeSpan difference = second - first;

这将返回一个 TimeSpan object ，您可以轻松查询，例如

if (difference.Days >= 8) ...

将 Days 的数量转换为周应该是一个微不足道的练习，因为每周正好有 7 天...

(请注意，Days 将为您提供整数天数，而 TotalDays 将包括小数天数。)