<% using (Html.BeginForm())
         { %>       
     <%= Html.ValidationSummary(true, "必要的信息请输入")%>
    分类名称:<%=Html.TextBox("typename")%>&nbsp; <%= Html.ValidationMessage("typename")%><br />
    是否可见:<%=Html.CheckBox("isvisible")%><br />     
  <input type="submit"  value="tijiao" />   
    <%}%>

 [AcceptVerbs(HttpVerbs.Post)]
        public ActionResult typeadd(string typename, bool isvisible)
        {         

            Dal.typenews tn = new Dal.typenews();
            Model.typenews model = new Model.typenews();

            if (ModelState.IsValid)
            {  
                model.typename = Server.HtmlEncode(typename);
                model.isvisible = isvisible;

                if (tn.Add(model) > 0)
                {
                   //添加成功,跳转到列表页
                    Response.Redirect("typelist");
                }
            }
            return View(model);
        }

  if (this.IsPost)
            {
                TryUpdateModel(user, new string[] {"Email", "Name", "Password", "NickName"});

                if (string.IsNullOrEmpty(user.Email))
                {
                    ModelState.AddModelError("Email", "请填写邮箱.");
                }
                else if (this.UserService.FindByEmail(user.Email) != null)
                {
                    ModelState.AddModelError("Email", "该邮箱已经被使用.");
                }

                if (string.IsNullOrEmpty(user.Name))
                {
                    ModelState.AddModelError("Name", "请填写用户名.");
                }
                else if (this.UserService.FindByName(user.Name) != null)
                {
                    ModelState.AddModelError("Name", "该用户名已经被使用.");
                }
                        ...

------解决方案--------------------

C# code

  if (ModelState.IsValid)
                {
                    this.UserService.Save(user);
                }
            }
            return View(user);