[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method,Inherited = true,AllowMultiple = true)]
public class AuthorizeAttribute : System.Web.Mvc.AuthorizeAttribute
{
    protected override void HandleUnauthorizedRequest(System.Web.Mvc.AuthorizationContext filterContext)
    {
        if (filterContext.HttpContext.Request.IsAuthenticated)
        {
            filterContext.Result = new System.Web.Mvc.HttpStatusCodeResult(403);
        }
        else
        {
            base.HandleUnauthorizedRequest(filterContext);
        }
    }
}

现在在web.config中我已经配置了403错误页面

<customErrors defaultRedirect="/Shared/Error" mode="On">
  <error statusCode="403" redirect="/Shared/UnAuthorize" />
</customErrors>

但浏览器仍然显示403的默认错误页面,
我在这里错过什么,任何想法