C# 今天星期幾

           string timeweek = "";
            string timekey = DateTime.Parse(newtime.Substring(0, 4) + "/" + newtime.Substring(4, 2) + "/" + newtime.Substring(6, 2)).DayOfWeek.ToString();
            if (timekey == "Sunday")
            {
                timeweek = "星期日";
            }
            else if (timekey == "Monday")
            {
                timeweek = "星期一";
            }
            else if (timekey == "Tuesday")
            {
                timeweek = "星期二";
            }
            else if (timekey == "Wednesday")
            {
                timeweek = "星期三";
            }
            else if (timekey == "Thursday")
            {
                timeweek = "星期四";
            }
            else if (timekey == "Friday")
            {
                timeweek = "星期五";
            }
            else if (timekey == "Saturday")
            {
                timeweek = "星期六";
            }