为什么它不想返回索引 MVC

Question

返回总是像图像一样的错误，我已经多次更改逻辑但我想成为这样

主页 Controller：

[HttpPost]
[AllowAnonymous]
public ActionResult Login(pd_user model, string returnUrl)
{
    proddevEntities1 db = new proddevEntities1();

    var dataItem = db.pd_user.FirstOrDefault(x => x.us_usrname == model.us_usrname && x.us_pwd == model.us_pwd);

    if (dataItem != null)
    {
        FormsAuthentication.SetAuthCookie(dataItem.us_usrname, false);

        if (Url.IsLocalUrl(returnUrl))
        {
            return Redirect(returnUrl);
        }
        else
            return RedirectToAction("Index");
    }
    else
    {
        ModelState.AddModelError("", "Invalid user/pass");
        return View();
    }
}

登录视图：

@using (Html.BeginForm("Login", "Home", new { ReturnUrl = Request.QueryString["ReturnUrl"] }, FormMethod.Post))
{
    @Html.AntiForgeryToken()
}

我尝试登录时的返回