MVC 模型js远程校验的使用方法

 　　　　[Required(ErrorMessage = "用户名不能为空"), Remote("ValidateUserName", "CommonWebApi", AreaReference.UseRoot, ErrorMessage = "用户名已被占用")]
        [StringLength(100, ErrorMessage = "{0} 至少包含 {2} 个字符。", MinimumLength = 5)]
        [Display(Name = "用户名")]
        public string UserName { get; set; }

 /// <summary>
        /// 找回密码验证用户名是否存在
        /// </summary>
        /// <param name="userName"></param>
        /// <returns></returns>
        public ActionResult VerifyUserName(string userName)
        {
            var user = _userProfileRepository.All().FirstOrDefault(item => item.UserName == userName);
            return Content(user == null ? "false" : "true");
        }

        public JsonResult GetAddressByGeo(decimal latitude,decimal longitude)
        {
            var address = _geoCodingInvoker.GetGeoAddressByCoordinate(latitude, longitude);
            return Json(address,JsonRequestBehavior.AllowGet);
        }