如何减去导致天或周的两个日期

Question

我正在寻找一个可以输入 2 个日期的函数：

像这样开始：

         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

下面尝试了这个函数，但它给了我一个负日期（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

您可以直接减去日期：

TimeSpan difference = second - first;

这将返回一个 TimeSpan 对象，您可以轻松查询该对象，例如

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

将Days数转换为周数应该是一项微不足道的练习，因为每周正好有 7 天......

（请注意，Days 将以整数形式提供天数，而TotalDays将包括小数天数。

Answer 2

您可以使用时间

跨度类

    public static String getWeekOrMonthFromDateDiff(DateTime first, DateTime second)
    {
        var span = second - first;
        if (span.Days <= 7)
            return span.Days + " day(s)";
        else
            return span.Days / 7 + " week(s)"; 
    }

Answer 3

你可以

简单地做

TimeSpan diff = first - second;

然后你可以做

int weekCount = diff.TotalDays / 7;

Answer 4

几天前我做了这样的事情：

private string GetTimeSpan(DateTime toDateTime, DateTime fromDateTime)
    {
        TimeSpan ts = toDateTime- fromDateTime;
        if (ts.Days < 0)
        {
            return "since " + ts.Days.ToString().Replace("-", string.Empty) + " Days";
        }
        else if (ts.Hours < 1)
        {
            return "in " + ts.Minutes + " Minutes";
        }
        else if (ts.Days < 1)
        {
            return "in " + ts.Hours + " Hours";
        }
        else if (ts.Days < 7)
        {
            return "in " + ts.Days + " Days";
        }
        else
        {
            return "in " + ts.Days / 7 + " Weeks";
        }
    }

按照您需要的方式修改它:)

Answer 5

对于这样的时间长度，您应该使用TimeSpan而不是DateTime，然后从属性TotalDays计算周数。

Answer 6

void func(DateTime t1, DateTime t2)
{
    days = (t2 - t1).TotalDays;
    weeks = days/7;
    year = weeks/52;
}