C# (CSharp) BackButtonVisibilityChangeRequested примеры использования

Пример #1

 protected void ShowBackButton()
 {
     BackButtonVisibilityChangeRequested?.Invoke(this, new NavigationButtonVisibilityChangeRequestEventArgs(true));
 }

Пример #2

 protected void HideBackButton()
 {
     BackButtonVisibilityChangeRequested?.Invoke(this, new NavigationButtonVisibilityChangeRequestEventArgs(false));
 }