AdvancedLauncher.UI.Windows.PagesWindow.OnTabChanged C# (CSharp) Метод

        private void OnTabChanged(object sender, SelectionChangedEventArgs e)
        {
            PageItemViewModel selectedTab = NavControl.SelectedValue as PageItemViewModel;
            if (selectedTab == null) {
                return;
            }
            PageContainer selectedPage = selectedTab.Item.Content as PageContainer;
            if (selectedPage != null) {
                //Prevent handling over changing inside tab item
                if (currentTab == selectedPage) {
                    return;
                }
                if (currentTab != null) {
                    try {
                        currentTab.OnClose();
                    } catch (AppDomainUnloadedException) { }
                }
                currentTab = selectedPage;
                currentTab.OnShow();
            }
        }