C# .net 对外接口返回json字符串序列化

UserBankCard userBankCard = new UserBankCard()
            {
                BankCard = bankCard,
                UserID = userID,
                RealName = realName,
                IDCard = IdCard,
                Phone = cardPhone,
                IsDefault = isDefault
            };
            string key = ConfigurationManager.AppSettings["JuHeBankCardKey"];

            //string bankcard = "6216910310203614";
            //银行卡类型及真伪查询，接口请求地址
            string apiUrl = "http://v.juhe.cn/bankcardinfo/query";

            string resultJson = BankPayHelper.JuHeHttpPost(apiUrl, key, bankCard);
            //string resultJson = " { \"reason\":\"查询成功 \",\"result\":{ \"bank\":\"中国民生银行\",\"cardtype\":\"借记卡\",\"nature\":\"借记卡普卡\",\"kefu\":\"95568\",\"bankcard\":\"621691031020361\",\"logo\":\"http://apiserver.qiniudn.com/minsheng.png\",\"info\":\"\"},\"error_code\":0}          ";
            if (RegExp.IsNull(resultJson))
            {
                return Json(JsonAjax.JsonResult("0", "返回请求Json为空，请检查日志"));
            }
            try
            {
                JuheBankCardResponse bankCardResponse = new JuheBankCardResponse();
                List<JuHeBankCardResult> bankCardResult = new List<JuHeBankCardResult>();
                bankCardResponse.result = bankCardResult;
                Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(resultJson);
                foreach (var item in dic)
                {
                    if (item.Key == "reason")
                    {
                        bankCardResponse.reason = item.Value.ToString();
                    }
                    if (item.Key == "result")
                    {
                        if (item.Value != null)
                        {
                            JuHeBankCardResult bankCardResultDic = new JuHeBankCardResult();
                            bankCardResultDic = JsonConvert.DeserializeObject<JuHeBankCardResult>(item.Value.ToString());
                            bankCardResult.Add(bankCardResultDic);
                            userBankCard.BankName = bankCardResultDic.bank;
                            userBankCard.CardType = bankCardResultDic.cardtype;
                            userBankCard.CardNature = bankCardResultDic.nature;
                            userBankCard.Kefu = bankCardResultDic.kefu;
                            userBankCard.LogoUrl = bankCardResultDic.logo;
                            userBankCard.BankInfo = bankCardResultDic.info;
                            userBankCard.Status = (int)BankCardStatus.Normal;//是否删除
                            userBankCard.CreateDate = DateTime.Now;
                            userBankCard.UpdateDate = null;
                        }
                    }
                    if (item.Key == "error_code")
                    {
                        bankCardResponse.error_code = Convert.ToInt32(item.Value);
                        if (Convert.ToInt32(item.Value) != 0)
                        {
                            LogHelper.Error("[ShopBankCard]银行支付银行卡类型及真伪查询失败，查询的银行卡号：" + bankCard + "。接口返回失败原因：" + bankCardResponse.reason + "。" + currentPageLog);
                            return Json(JsonAjax.JsonResult("0", "银行卡类型及真伪查询失败，" + bankCardResponse.reason));
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                LogHelper.RecordErro("银行卡类型及真伪查询报错" + currentPageLog, ex);
                return Json(JsonAjax.JsonResult("-1", "银行卡类型及真伪查询报错"));
            }