c#获取流水单号

/// <summary>         /// 获取问题单号         /// </summary>         /// <returns></returns>         public string GetOrderNumber(ZemtProblemManagementDBContext dbContext)         {             int index = 0;             int state = Convert.ToInt32(DBStateEnum.Normal);             var resultList = dbContext.TProblems.Where(x =>x.DBStatus == state.ToString() && x.CreateTime.Month == DateTime.Now.Month);             if (resultList.Count() == 0)             {                 //没有已经提交的就是1                 index = 1;             }             else             {                 //如果有1一个已经提交的那么下一个就是+1                 index = resultList.Count() + 1;             }             string orderNo = "";             do             {                 orderNo = "WT" + DateTime.Now.ToString("-yyyyMM-") + index.ToString().PadLeft(6, '0');                 if (dbContext.TProblems.Count(x => x.OrderNumber.ToUpper() == orderNo.ToUpper()) > 0)                 {                     index++;                 }                 else                 {                     break;                 }             } while (1 == 1);             return orderNo;         }