Question

I am trying to implement drag and drop for a treeview control that binds to custom elements:

<TreeView ItemsSource="{Binding FirstGeneration}">
  <TreeView.Resources>
     <HierarchicalDataTemplate DataType="{x:Type NavigationTreeElement}" 
                               ItemsSource="{Binding Children}">
       <StackPanel Orientation="Horizontal" Margin="1">
          <Image Source="open-16x16.png" />
          <TextBlock Text="{Binding Path=DisplayName}" />
       </StackPanel>
     </HierarchicalDataTemplate>
  </TreeView.Resources>
</TreeView>

With the underlying class:

 public class NavigationElement
 {
     public string DisplayName { get; set; }
     public ObservableCollection<NavigationElement> Children { get; set; }
 }

I’m having a problem with associating the rendered TreeViewItem with the underlying NavigationElement. If I find a TreeViewItem that the mouse is over, as such:

    private static TreeViewItem GetNearestContainer(UIElement element)
    {
        // Walk up the element tree to the nearest tree view item.
        var container = element as TreeViewItem;
        while ((container == null) && (element != null))
        {
            element = VisualTreeHelper.GetParent(element) as UIElement;
            container = element as TreeViewItem;
        }
        return container;
    }

How do I associate that TreeViewItem with an underlying NavigationElement?

Answer 1

I think it’s in container.Header, odd as that might seem.