ModelState.IsValid

model内的设置如下所示：

/// <summary>
        /// 取得或设置邮编
        /// </summary>
        [RegularExpression(@"(^[1-9]d{5}$)", ErrorMessage = "邮编不符合规范！")]
        public string Zip
        {
            get
            {
                return _Zip;
            }
            set
            {
                if (_Zip != value)
                {
                    _Zip = string.IsNullOrEmpty(value) ? value : value.Trim();
                    OnPropertyChanged("Zip");
                }
            }
        }

 /// <summary>
        /// 添加人员
        /// </summary>
        /// <param name="memberVO">客户端人员对象</param>
        /// <returns></returns>
        [HttpPost]
        public dynamic AddMember(MemberVO memberVO)
        {
            if (ModelState.IsValid)
            {
                var member = SaveMember(memberVO);
                HttpResponseMessage httpResponseMessage = Request.CreateResponse(HttpStatusCode.Created, member.MemberToMemberVO(User, Database));

                return httpResponseMessage;
            }
            Log(ModelState);
            return Request.CreateResponse(HttpStatusCode.InternalServerError);
        }

相当于服务器对客户端model的一种验证。model实例如在服务器端不符合要求则会报错。