title: how to access elements in a StackPanel in listbox
body: <p>I have a <code>ListBox</code> that contains a <code>StackPanel</code> which contains an <code>Image</code> and a <code>TextBlock</code>. I want to access the <code>TextBlock</code> via c# (code-behind) to change it's font manually.</p>
  
  <p>Relevent XAML:</p>
  
  <pre><code>&lt;ListBox x:Name="CategoriesListBox" Margin="0,0,-12,0" ItemsSource="{Binding Categories}" SelectionChanged="CategoriesListBox_SelectionChanged" &gt;
              &lt;ListBox.ItemTemplate&gt;
                  &lt;DataTemplate&gt;
                      &lt;StackPanel Margin="0,0,0,17" Width="432" Height="62"&gt;
                          &lt;Grid&gt;
                              &lt;Grid.ColumnDefinitions&gt;
                                  &lt;ColumnDefinition Width="40"/&gt;
                                  &lt;ColumnDefinition Width="*"/&gt;
                              &lt;/Grid.ColumnDefinitions&gt;
                              &lt;Image x:Name="catImage" Source="{Binding icon}"/&gt;
                              &lt;TextBlock x:Name="catName"  Grid.Column="1" Text="{Binding name_shown}" TextWrapping="Wrap" Style="{StaticResource PhoneTextLargeStyle}"/&gt;
                          &lt;/Grid&gt;
                      &lt;/StackPanel&gt;
                  &lt;/DataTemplate&gt;
              &lt;/ListBox.ItemTemplate&gt;
          &lt;/ListBox&gt;
  </code></pre>
  
  <p>I need to access the "catName" <code>TextBlock</code> for all cells.</p>