C# 将datatime类型转为Cron

  /// <summary>
        /// datetime修改为corn表达式用于自动预测
        /// </summary>
        /// <param name="time"></param>
        /// <returns></returns>
        public string DatetimeToCron(string time,string Week)
        {
            var cronValue = "";
            string weekCron = "? * *";
            try
            {
                switch (Week)
                {
                    case "星期一":
                        weekCron = "? * 2";
                        break;
                    case "星期二":
                        weekCron = "? * 3";
                        break;
                    case "星期三":
                        weekCron = "? * 4";
                        break;
                    case "星期四":
                        weekCron = "? * 5";
                        break;
                    case "星期五":
                        weekCron = "? * 6";
                        break;
                    case "星期六":
                        weekCron = "? * 7";
                        break;
                    case "星期日":
                        weekCron = "? * 1";
                        break;

                }
                if (string.IsNullOrWhiteSpace(time)) return "";
                string error = "传入的时间值[" + time + "]格式有误!";
                int ss = 0, mi = 0, hh = 0;
                if (time.Length < 5) throw new Exception(error);
                if (time.Substring(2, 1) != ":") throw new Exception(error);

                if (!int.TryParse(time.Substring(0, 2), out hh))
                    throw new Exception(error);
                if (!int.TryParse(time.Substring(3, 2), out mi))
                    throw new Exception(error);
                if (time.Length > 5)
                {
                    if (time.Substring(5, 1) != ":") throw new Exception(error);
                    if (!int.TryParse(time.Substring(6), out ss))
                        throw new Exception(error);
                }
                if (ss > 59) throw new Exception(error);
                if (mi > 59) throw new Exception(error);
                if (hh > 23) throw new Exception(error);
                cronValue = ss + " " + mi + " " + hh + " " + weekCron;

            }
            catch (Exception e)
            {

                LogHelper.WriteLog("datetime修改为corn表达式用于自动预测", e);
            }

            return cronValue;

        }