C#获取指定日期为一年中的第几周

/// <summary>

/// 获取指定日期，在为一年中为第几周

/// </summary>

/// <param name="dt">指定时间</param>

/// <reutrn>返回第几周</reutrn>

private static int GetWeekOfYear(DateTime dt)

{

GregorianCalendar gc = new GregorianCalendar();

int weekOfYear = gc.GetWeekOfYear(dt,CalendarWeekRule.FirstDay, DayOfWeek.Monday);

return weekOfYear;

}