public HttpResponseBase GetVendorProductSpec()
 {
     string json = string.Empty;
     DataTable _dt = new DataTable();
     ProductQuery query = new ProductQuery();
     int totalCount = 0;
     try
     {
         query.Start = Convert.ToInt32(Request.Params["start"] ?? "0");
         query.Limit = Convert.ToInt32(Request.Params["limit"] ?? "25");
         query.Product_Id = Convert.ToUInt32(Request.Params["product_id"]);
         _IProductMgr = new ProductMgr(mySqlConnectionString);
         _dt = _IProductMgr.GetVendorProductSpec(query, out  totalCount);
         IsoDateTimeConverter timeConverter = new IsoDateTimeConverter();
         timeConverter.DateTimeFormat = "yyyy-MM-dd HH:mm:ss";
         json = "{success:true,totalCount:" + totalCount + ",data:" + JsonConvert.SerializeObject(_dt, Formatting.Indented, timeConverter) + "}";
     }
     catch (Exception ex)
     {
         Log4NetCustom.LogMessage logMessage = new Log4NetCustom.LogMessage();
         logMessage.Content = string.Format("TargetSite:{0},Source:{1},Message:{2}", ex.TargetSite.Name, ex.Source, ex.Message);
         logMessage.MethodName = System.Reflection.MethodBase.GetCurrentMethod().Name;
         log.Error(logMessage);
         json = "{success:false,totalCount:0,data:[]}";
     }
     this.Response.Clear();
     this.Response.Write(json.ToString());
     this.Response.End();
     return this.Response;
 }