如何在没有周末的情况下获取DateTime.DaysInMonth？

Question

如何获得C＃中没有星期五和星期六的一个月内的天数？

Answer 1

这里，快速和肮脏的：

class Program 
{ 
    static void Main(string[] args) 
    { 
     int month = DateTime.Today.Month; 
     int year = DateTime.Today.Year; 

     int daysInMonthMinusFridayAndSaturday = 0; 

     for (int i = 1; i <= DateTime.DaysInMonth(year,month); i++) 
     { 
      DateTime thisDay = new DateTime(year,month,i); 
      if(thisDay.DayOfWeek != DayOfWeek.Friday && thisDay.DayOfWeek != DayOfWeek.Saturday) 
      { 
       daysInMonthMinusFridayAndSaturday += 1; 
      } 
     } 

     Console.WriteLine(daysInMonthMinusFridayAndSaturday); 
     Console.ReadLine(); 
    } 
} 

Answer 2

我会避免循环或迭代，做这样的：

int GetWorkDays(int year, int month) 
{ 
    var firstDayOfMonth = new DateTime(year, month, 1).DayOfWeek; 
    var daysInMonth = DateTime.DaysInMonth(year, month); 

    // count whole weeks first    
    var wholeWeeks = daysInMonth/7; 
    var extraDays = daysInMonth % 7; 

    // calculate the overlap of the "remainder days" with the weekend. 
    var lastDayOfMonth = (int) (firstDayOfMonth + extraDays - 1); 
    var overlapStart = Math.Max((int) firstDayOfMonth, (int) DayOfWeek.Friday); 
    var overlapEnd = Math.Min(lastDayOfMonth, (int) DayOfWeek.Saturday); 
    var weekendOverlap = Math.Max(0, overlapEnd - overlapStart + 1); 

    // substract weekend days 
    return daysInMonth - wholeWeeks * 2 - weekendOverlap; 
} 

Answer 3

强制性LINQ的解决方案：

int days = Enumerable.Range(1, DateTime.DaysInMonth(year, month)) 
        .Select(day => new DateTime(year, month, day)) 
        .Count(d => d.DayOfWeek != DayOfWeek.Saturday && 
            d.DayOfWeek != DayOfWeek.Friday);