public JsonResult DeleteFile(string models)
 {
     JsonResult result = new JsonResult();
     Download bll = new Download();
     List<sd_download> fileList = new List<sd_download>();
     sd_download info = new sd_download();
     if (models != null)
     {
         var t = JsonConvert.DeserializeObject<List<sd_download>>(models);
         if (t.Count > 0)
         {
             bll.Delete(t);
             result.Data = fileList;
         }
     }
     return result;
 }
 public JsonResult UpdateFile(string models)
 {
     JsonResult result = new JsonResult();
     Download bll = new Download();
     List<sd_download> fileList = new List<sd_download>();
     sd_download info = new sd_download();
     if (models != null)
     {
         if (models.StartsWith("["))
         {
             var jarr = JArray.Parse(models);
             if (jarr.Count > 0)
             {
                 foreach (var item in jarr)
                 {
                     info = Newtonsoft.Json.JsonConvert.DeserializeObject<sd_download>(item.ToString());
                     fileList.Add(info);
                 }
                 if (fileList.Count > 0)
                 {
                     bll.Update(fileList);
                     result.Data = fileList;
                 }
             }
         }
     }
     return result;
 }