BaconographyWP8.View.MessagingPageView.UpdateMenuItems C# (CSharp) Method

        private void UpdateMenuItems()
        {
            if (_appBarButtons == null || ApplicationBar.Buttons.Count == 0)
                BuildAppBar();

            var vm = this.DataContext as MessagesViewModel;
            if (vm != null)
            {
                // TODO: If item in current pivot selected, enable reply/delete
                if (vm.SelectedItem != null)
                {
                    if (vm.SelectedItem.IsPostReply || vm.SelectedItem.IsCommentReply || vm.SelectedItem.IsUserMention)
                    {
                        _appBarButtons[1].Text = "context";
                        _appBarButtons[1].IconUri = new Uri("\\Assets\\Icons\\goto.png", UriKind.Relative);
                    }
                    else
                    {
                        _appBarButtons[1].IconUri = new Uri("\\Assets\\Icons\\reply.png", UriKind.Relative);
                        _appBarButtons[1].Text = "reply";
                    }

                    _appBarButtons[1].IsEnabled = true;
                }
                else
                {
                    _appBarButtons[1].IsEnabled = false;
                }
            }
        }