Self-Referencing Binding

[Sergiy]

Hi, 

I have got model:

public class Category
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int? ParentCategoryId { get; set; }
    public virtual Category ParentCategory { get; set; }
    public virtual ICollection<Category> SubCategories { get; set; }
}

And in MVVM:

private ObservableCollection<Category> _categories;
public ObservableCollection<Category> Categories
{
    get { return _categories; }
    set
    {
        if (_categories == value) return;

        _categories = value;
        OnPropertyChanged("Categories");
    }
}

I found an example, but I don't want to create a new model, and even more so to edit an existing one.
Could you explain to me step-by-step, how I can bind the data to treeview (with parents and their childs')?

[Sergiy]

thanks, I understand and wrote the following code

      

public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
      {
          var category = value as Category;
          if (null != category)
          {
                  if (category.SubCategories.Count > 0)
                  {
                      return category.SubCategories.Where(i => i.ParentCategoryId == category.Id);
                  }
          }

          var categories = value as ObservableCollection<Category>;
          if (categories != null && categories.Count > 0)
          {
              return new ObservableCollection<Category>(categories.Where(c => c.ParentCategory == null));
          }


          return null;
      }

and xaml

<t:RadTreeView       SelectedValuePath="Name"
               ItemsSource="{Binding Categories, Converter={StaticResource treeHierarchyConverter}}">

    <t:RadTreeView.ItemTemplate>
        <HierarchicalDataTemplate
            ItemsSource="{Binding Converter={StaticResource treeHierarchyConverter}}">
            <TextBlock Text="{Binding Name}" />
        </HierarchicalDataTemplate>
    </t:RadTreeView.ItemTemplate>
</t:RadTreeView>