我必须找出具有给定日期的月份中的某天,比方说我具有01/26/2020日期,现在日期26是该月的第4个星期日,如何找出月份中具有可重复计数的日期?
没有直接的方法可以实现。您需要调用以下代码。
DateTime dateValue = new DateTime(2019, 12, 19);
int getDayOfWeek = GetWeekNumberOfMonth(dateValue);
//convert to ordinal
string ordinalWeekOfMonth = AddOrdinal(getDayOfWeek);
Console.WriteLine(ordinalWeekOfMonth + " " + dateValue.DayOfWeek);//output like 2nd sunday
以下相关方法可用于调用上面的代码
public static int GetWeekNumberOfMonth(DateTime date)
{
date = date.Date;
DateTime firstMonthDay = new DateTime(date.Year, date.Month, 1);
DateTime firstMonthMonday = firstMonthDay.AddDays((DayOfWeek.Monday + 7 - firstMonthDay.DayOfWeek) % 7);
if (firstMonthMonday > date)
{
firstMonthDay = firstMonthDay.AddMonths(-1);
firstMonthMonday = firstMonthDay.AddDays((DayOfWeek.Monday + 7 - firstMonthDay.DayOfWeek) % 7);
}
return (date - firstMonthMonday).Days / 7 + 1;
}
public static string AddOrdinal(int num)
{
if (num <= 0) return num.ToString();
switch (num % 100)
{
case 11:
case 12:
case 13:
return num + "th";
}
switch (num % 10)
{
case 1:
return num + "st";
case 2:
return num + "nd";
case 3:
return num + "rd";
default:
return num + "th";
}
}