C#如何计算不包括特定日期的工作日（假期）

Question

我阅读了一些与 C# 中的函数相关的问题/答案来计算工作日（从星期一到星期五的天数）；有些使用扩展代码来实现这一点。

我有一个包含 50,000 多行的数据表，我需要一种有效的方法来计算这些信息。

Answer 1

基于@MiBols 的回答，一个更有效的解决方案是使用 aHashSet<DateTime>而不是List<DateTime>where search is then in O(1)：

/// <summary> Get working days between two dates (Excluding a list of dates - Holidays) </summary>
/// <param name="dtmCurrent">Current date time</param>
/// <param name="dtmFinishDate">Finish date time</param>
/// <param name="excludedDates">Collection of dates to exclude (Holidays)</param>
public static int fwGetWorkingDays(this DateTime dtmCurrent, DateTime dtmFinishDate, 
                                   HashSet<DateTime> excludedDates)
{
    Func<DateTime, bool> workDay = currentDate => (
        currentDate.DayOfWeek == DayOfWeek.Saturday ||
        currentDate.DayOfWeek == DayOfWeek.Sunday ||
        excludedDates.Contains(currentDate.Date));

    return Enumerable.Range(0, 1 + (dtmFinishDate - dtmCurrent).Days)
        .Count(intDay => workDay(dtmCurrent.AddDays(intDay)));
}