为什么可视化树中有2个ListBoxItems

我只显示ListBox的选定元素（是的，我知道）。。。我试图理解为什么如果我有一个ListBox.ItemTemplate和ListBoxItem的一个子项，我必须遍历2个ListBoxItems才能访问名为"thisListBoxItem"的元素？似乎应该只有一个可视的ListBoxItem元素。

我的XAML

<ListBox Name="cjisDisplayItemListBox" SelectionChanged="cjisDisplayItemListBox_SelectionChanged_1">
  <ListBox.ItemTemplate >
    <DataTemplate>
      <ListBoxItem Name="thisListBoxItem" Visibility="Collapsed">
      <!-- some TextBlocks with bindings here --> 
      </ListBoxItem>
    </DataTemplate>
  </ListBox.ItemTemplate>
</ListBox>

//首先，我将SelectedItem强制转换为ListBoxItem（myListBoxItem）//那么我必须通过FindName属性下降到较低的ListBoxItem。。

private void cjisDisplayItemListBox_SelectionChanged_1(object sender, SelectionChangedEventArgs e)
                    {
                        ListBox lb = sender as ListBox;
                        object item = lb.SelectedItem as object;
                        ListBoxItem myListBoxItem = (ListBoxItem)(lb.ItemContainerGenerator.ContainerFromItem(item));
                        ContentPresenter myContentPresenter = FindVisualChild<ContentPresenter>(myListBoxItem);
                        if (myContentPresenter == null) return;
                        DataTemplate myDataTemplate = myContentPresenter.ContentTemplate;
                        ListBoxItem temp = (ListBoxItem)myDataTemplate.FindName("thisListBoxItem", myContentPresenter);
                        if (myListBoxItem.IsSelected) temp.Visibility = System.Windows.Visibility.Visible;
                    }