private void SetItemsSource(IEnumerable value)
{
var itemsSource = new ObservableCollection <object>();
FlatItemsSource = new FlatCollection(new ItemsSourceHierarchicalSource(value, this), itemsSource);
// now setting the flat source that the ItemsControl will use
SetItemsSource(itemsSource);
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualTreeView"/> class.
/// </summary>
public VirtualTreeView()
{
FlatItems = new FlatCollection(new ItemHierarchicalSource(HierarchicalItems), Items);
HierarchicalItems.IfType <INotifyCollectionChanged>(nc => nc.CollectionChanged += OnHierarchicalItemsCollectionChanged);
SelectedItems.CollectionChanged += OnSelectedItemsCollectionChanged;
}
