C# FormsAuthentication对象已过时[使用MVC5],c#,forms-authentication,dotnetopenauth,asp.net-mvc-5,owin,C#,Forms Authentication,Dotnetopenauth,Asp.net Mvc 5,Owin,我在MVC5站点中使用以下代码： [HttpPost] [ValidateAntiForgeryToken] public ActionResult Login(LoginModel loginModel) { if (ModelState.IsValid) { var authenticated = FormsAuthentication.Authenticate(loginModel.UserName, loginModel.Password); if