<configuration>
 <appSettings>  
  <add key="ClientValidationEnabled" value="true" />
  <add key="UnobtrusiveJavaScriptEnabled" value="true" />
 </appSettings>
</configuration>

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;

namespace Server_Side_Validation_IN_MVC.Models
{
  public class StudentServer
  {
    [Required(ErrorMessage="Name为必填项")]
    public string Name { get; set; }

    [Required(ErrorMessage="电子邮件必须")]
    [EmailAddress(ErrorMessage="电子邮件格式不对")]
    public string Email { get; set; }
  }
}

public ActionResult SeverSideIndex()
    {
      return View();
    }

    [HttpPost]
    public ActionResult SeverSideIndex(StudentServer model)
    {
      if (ModelState.IsValid)
      {
        ViewBag.Name = model.Name;
        ViewBag.Email = model.Email;
      }
      return View();

    }

 public static void RegisterRoutes(RouteCollection routes)
    {
      routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

      routes.MapRoute(
        name: "Default",
        url: "{controller}/{action}/{id}",
        defaults: new { controller = "Student", action = "SeverSideIndex", id = UrlParameter.Optional }
      );
    }