private static async void FinishCreatingAsyncVoid(BackButton backButton, Frame frame, NavigationService service) { await Task.CompletedTask; // TODO: add this feature back in if you can figure out the reason for an err // await ClearExpiredCacheAsync(service); service.BackButtonHandling = backButton; if (backButton == BackButton.Attach) { frame.RegisterPropertyChangedCallback(Frame.CanGoBackProperty, (s, args) => GestureService.UpdateBackButton(service.CanGoBack)); Central.Messenger.Subscribe <Messages.BackRequestedMessage>(frame, async m => { await service.GoBackAsync(); }); } if (!Instances.Any()) { Default = service; } Instances.Register(service); Central.Messenger.Send(new Messages.NavigationServiceCreatedMessage { NavigationService = service, BackButtonHandling = backButton, IsDefault = Default == service, Dispatcher = service.GetDispatcher() }); }