如何计算两个日期之间的工作日数

Question

我必须计算C＃中两个给定日期之间的工作日数量。我已经在整个互联网上进行了搜索（甚至在StackOverflow上），但找不到解决我问题的好方法...这就是我现在所拥有的：

public int WorkDays(DateTime startDate, DateTime endDate)
    {
        int days = 0;
        while (startDate <= endDate)
        {
            if (startDate.DayOfWeek != DayOfWeek.Saturday && startDate.DayOfWeek != DayOfWeek.Sunday)
            {
                ++days;
            }
            startDate = startDate.AddDays(1);
        }
        return days;
    }

这是我猜应该可以进行的测试：

[TestMethod]
    public void TestWorkdays()
    {
        var calc = new WorkDayCalculator();
        Assert.AreEqual(14, calc.WorkDays(new DateTime(2012, 10, 1), new DateTime(2012, 10, 18)));
        Assert.AreEqual(10, calc.WorkDays(new DateTime(2012, 10, 6), new DateTime(2012, 10, 21)));
        Assert.AreEqual(12, calc.WorkDays(new DateTime(2012, 10, 5), new DateTime(2012, 10, 22)));

        // over maand heen
        Assert.AreEqual(5, calc.WorkDays(new DateTime(2012, 10, 29), new DateTime(2012, 11, 4)));
        // over jaar heen (precies 52 weken)
        Assert.AreEqual(260, calc.WorkDays(new DateTime(2011, 10, 10), new DateTime(2012, 10, 5)));
        // startdatum > einddatum! (bad path)
        Assert.AreEqual(-40, calc.WorkDays(new DateTime(2012, 12, 29), new DateTime(2012, 11, 4)));
    }