/// <summary>
        /// 获取token
        /// </summary>
        /// <returns></returns>
        private string GetAuthToken()
        {
            string objCache = _cacheService.Get <string>(CacheKey.GETUIAUTHTOKEN);

            if (objCache == null)
            {
                string authToken = string.Empty;
                string timestamp = DateTime.Now.GetTimeSpan().ToString();
                var    url       = string.Format("https://restapi.getui.com/v1/{0}/auth_sign", _appId);
                var    data      = new JObject();
                string sign      = HashEncrypt.GetSHA256(_appKey + timestamp + _masterSecret);
                data.Add("sign", sign);
                data.Add("timestamp", timestamp);
                data.Add("appkey", _appKey);
                HttpHelper httpHelper = new HttpHelper(url, "application/json");
                string     result     = httpHelper.SendPost(data.ToString());
                JObject    json       = JObject.Parse(result);
                if (json["result"].ToString() == "ok")
                {
                    authToken = json["auth_token"].ToString();
                    _cacheService.Add(CacheKey.GETUIAUTHTOKEN, authToken, DateTime.Now.AddHours(23).GetTimeSpan());
                }
                return(authToken);
            }
            else
            {
                return(objCache);
            }
        }