如何访问列表框数据模板中的控件？

Hi I have the following code:

嗨，我有以下代码：

<ListBox x:Name="foldersListBox" Grid.Column="0" MouseLeftButtonUp="foldersListBox_MouseLeftButtonUp" 


                             BorderThickness="0"  Height="AUTO" 
                             ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                             ScrollViewer.VerticalScrollBarVisibility="Disabled">
                        <DataTemplate>
                            <Border BorderBrush="LightGray"
                            BorderThickness="2"
                            CornerRadius="4">
                                <Image x:Name="folderImage" Width="70" Height="70" Margin="3" />
                            </Border>
                        </DataTemplate>
</ListBox>
<Li