public class BasicAuthAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            var username = filterContext.HttpContext.Session["username"];
            var password = filterContext.HttpContext.Session["password"];
            if (username == null || password == null)

            {
                //用户不登陆的时候跳转到登录页面
                filterContext.Result = new RedirectToRouteResult(new RouteValueDictionary(new { controller = "Home", action = "Login", area = string.Empty }));
            }
        }
    }