我需要找到2個優(yōu)雅的完整實現(xiàn)public static DateTime AddBusinessDays(this DateTime date, int days){ // code here}and public static int GetBusinessDays(this DateTime start, DateTime end){ // code here}最好是O（1）（無循環(huán)）。編輯：工作日是指工作日（星期一，星期二，星期三，星期四，星期五）。沒有假期，只有周末除外。我已經(jīng)有了一些看起來可行的丑陋解決方案，但是我想知道是否有優(yōu)雅的方法可以做到這一點(diǎn)。謝謝這是我到目前為止所寫的。它在所有情況下均有效，并且也具有負(fù)面效果。仍然需要GetBusinessDays實施public static DateTime AddBusinessDays(this DateTime startDate,                                         int businessDays){    int direction = Math.Sign(businessDays);    if(direction == 1)    {        if(startDate.DayOfWeek == DayOfWeek.Saturday)        {            startDate = startDate.AddDays(2);            businessDays = businessDays - 1;        }        else if(startDate.DayOfWeek == DayOfWeek.Sunday)        {            startDate = startDate.AddDays(1);            businessDays = businessDays - 1;        }    }    else    {        if(startDate.DayOfWeek == DayOfWeek.Saturday)        {            startDate = startDate.AddDays(-1);            businessDays = businessDays + 1;        }        else if(startDate.DayOfWeek == DayOfWeek.Sunday)        {            startDate = startDate.AddDays(-2);            businessDays = businessDays + 1;        }    }    int initialDayOfWeek = (int)startDate.DayOfWeek;    int weeksBase = Math.Abs(businessDays / 5);    int addDays = Math.Abs(businessDays % 5);    if((direction == 1 && addDays + initialDayOfWeek > 5) ||         (direction == -1 && addDays >= initialDayOfWeek))    {        addDays += 2;    }    int totalDays = (weeksBase * 7) + addDays;    return startDate.AddDays(totalDays * direction);}