ASP.NET MVC实现登录后跳转到原界面

public class Student
{
    public string Name{get;set;}
    public string ReturnUrl{get;set;}
}

@using (Html.BeginForm("Index", "Home", FormMethod.Post))
{
    @Html.Hidden("ReturnUrl", Request.Url.PathAndQuery)
    @Html.TextBoxFor(m => m.Name)
    <input type="submit" value="提交"/>
}

public ActionResult Index()
{
    return View(new Student());
}
[HttpPost]
public ActionResult Index(Student student)
{
    return Redirect(student.ReturnUrl);
}

public ActionResult Index()
{
    return View(new Student());
}

    public class Student
    {
        public string Name { get; set; }
        public string ControllerName { get; set; }
        public string ActionName { get; set; }
    }

    public class HomeController : Controller
    {
        
        public ActionResult Index()
        {
            Student student = new Student()
            {
                ActionName = this.ControllerContext.RouteData.Values["action"].ToString(),
                ControllerName = this.ControllerContext.RouteData.Values["controller"].ToString()
            };
            return View(student);
        }
        [HttpPost]
        public ActionResult Index(Student student)
        {
            ViewBag.msg = "我又回来了~~";
            //如果是登录，先验证，验证成功执行下面的代码
            return View(student.ActionName, student);
        }
    }

@model MvcApplication1.Models.Student
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>Index</h2>
<div>@ViewBag.msg</div>
@using (Html.BeginForm("Index", "Home", FormMethod.Post))
{
    @Html.TextBoxFor(m => m.Name)
    <input type="submit" value="提交"/>
}