How to access Generated WPF controls after Data Binding

Question

Please consider the following XAML code:

<ListBox Name="listBox1" ItemsSource="{Binding}" >
    <ListBox.ItemTemplate>
        <DataTemplate>
            <Border Name="border1">
                <TextBlock Text="{Binding}" />
            </Border>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

and we assign a simple array to it:

listBox1.DataContext = new[] { "A", "B", "C" };

Now the question is how we can access the generated objects for Border (or TextBlock instances)?

• It is not possible by "border1". It does not exist.
• listBox1.ItemContainerGenerator.ContainerFromIndex(0) returns a ListBoxItem but content of that ListBoxItem is of type String.
• FindName("border1") returns null

Update: What I expect to find are 3 instances of Border (and 3 TextBlocks, one in each Border).

Answer 1

You can access it like so:

        DataTemplate dt = this.listBox1.ItemTemplate;
        Border border = dt.LoadContent() as Border;
        // Do something with border...

Answer 2

Once you get the ListBoxItem, you need to walk the visual tree to find what your looking for.

Dr WPF has some great articles about it here

Here is the code from that article to search for a descendant of a particular type

  public static Visual GetDescendantByType(Visual element, Type type)
  {
      if (element.GetType() == type) return element;

      Visual foundElement = null;

      if (element is FrameworkElement)
          (element as FrameworkElement).ApplyTemplate();

      for (int i = 0;
          i < VisualTreeHelper.GetChildrenCount(element); i++)
      {
          Visual visual = VisualTreeHelper.GetChild(element, i) as Visual;
          foundElement = GetDescendantByType(visual, type);
          if (foundElement != null)
              break;
      }

      return foundElement;
  }