是這樣的，今天遇到了這個問題，我加了try catch 後也只顯示這樣

這樣我還是不太清楚錯在哪裡，以下是我的程式碼

 public List<HDOrderListDto> FindAKHistory(string pat_guid, DateTime startDate, DateTime endDate)
        {
            if (String.IsNullOrWhiteSpace(pat_guid)) return null;
            List<HDOrderListDto> dtos = (from x in _repo.HD_ORDER
                         where x.PAT_GUID == pat_guid && x.ODR_DATE >= startDate && x.ODR_DATE <= endDate                       
                         select new HDOrderListDto
                         {                                             
                             OdrDate = x.ODR_DATE,
                             HDType = x.HD_TYPE,
                             AkCode = x.AK_CODE,
                             AkDesc = x.AK_DESC
                         }
                         ).OrderByDescending(x=>x.OdrDate).ToList<HDOrderListDto>();
            try
            {
                foreach (HDOrderListDto dto in dtos)
                {
                    if (dto.AkCode == "OTHER")
                    {
                        dto.AkName= dto.AkDesc;
                        continue;
                    }
                    if (dto.HDType == "HD") dto.AkName = _repo.NCODE.Where(x => x.CID == dto.CID && x.NC_ID == "HDO1001" && x.NC_CODE == dto.AkCode).FirstOrDefault<NCODE>().NC_NAME;
                    if (dto.HDType == "HDF") dto.AkName = _repo.NCODE.Where(x => x.CID == dto.CID && x.NC_ID == "HDO6001" && x.NC_CODE == dto.AkCode).FirstOrDefault<NCODE>().NC_NAME;
                }     
            }
            catch (Exception ex)
            {
                throw ex;
            }
                                     
            return dtos;
        }

想請問我try catch那段該如何下才能讓錯誤顯示得比較清楚?