private void buttonShowList_Click(object sender, RoutedEventArgs e) { if (isCollapsed) { listPersons.Visibility = Visibility.Visible; try { listPersons.ItemsSource = _db.GetAllPersons(); listPersons.DisplayMemberPath = "Name"; } catch { MessageBox.Show("Ошибка при запросе к базе данных."); } } else { listPersons.Visibility = Visibility.Collapsed; } isCollapsed = !isCollapsed; }