问AllowAnonymous属性不工作MVC 5

EN

[Authorize]
[RoutePrefix("users")]
public class UsersController : Controller
{
    [Route("register/{skypeid}")]
    public ActionResult Register(string skypeid)
    {
            ///stuff...            
        }
        catch (Exception ex)
        {
            return Content(ex + "");
        }

        ViewBag.Name = name;
        return View();

    }

    [AllowAnonymous]
    [Route("exists/{skypeid}")]
    public ActionResult Exists(string skypeid)
    {
        return Content("Hello " + skypeid);
    }