c# mvc modelstate

     [Required]
        [DisplayName("112")]

       var errs = new List<string>();
            if(ModelState.IsValid)
                return Json(save, JsonRequestBehavior.AllowGet);
            else
                foreach (var state in ModelState)
                {
                    foreach (var err in state.Value.Errors)
                    {
                        errs.Add(err.ErrorMessage);//把错误添加到数组里  
                    }
                }
            return Json(string.Join(",",errs), JsonRequestBehavior.AllowGet);