How to bind SharePoint list to WPF Treeview

Hi there,

In WPF in want to bind the List to the treeview, the first level is working, but how to get the next level.

What am i doing wrong?

Regards,

Edwin

code behind

using System;
using System.Collections.Generic;
using System.Windows;
using Microsoft.SharePoint.Client;
using System.ComponentModel;
using System.Linq;
using Microsoft.SharePoint.Linq;

namespace SharePoint2013
{
    /// <summary>
    /// Interaction logic for SP_List_Treeview.xaml
    /// </summary>
    public partial class SP_List_Treeview : Window, INotifyPropertyChanged
    {
        public SP_List_Treeview()
        {
            InitializeComponent();
            DataContext = this;
            _ctx = new ClientContext("http://server:15757/");
            _ctx.AuthenticationMode = ClientAuthenticationMode.Default;
        }

        ClientContext _ctx;

        IEnumerable<List> _lists;
        public IEnumerable<List> lists
        {
            get { return _lists; }
            set
            {
                if (_lists == value) return;

                _lists = value;
                OnPropertyChanged("lists");
            }
        }
        public void shardedDoc()
        {
            // Standard windows authentication
            _ctx.AuthenticationMode = ClientAuthenticationMode.Default;

            ListCollection tlists = _ctx.Web.Lists;
            _ctx.Load(tlists);

            IEnumerable<List> listsCollection =
                    _ctx.LoadQuery(
                                tlists.Include(l => l.Title, l => l.Id, l => l.RootFolder.Folders.Include(
                                    Folder => Folder.Name))
                                     .Where(list => !list.Hidden && list.BaseType == BaseType.DocumentLibrary));


            _ctx.ExecuteQuery();

            if (_ctx.HasPendingRequest)
            {
                MessageBox.Show("Pending: " + _ctx.HasPendingRequest.ToString());
                return;
            }
            lists = listsCollection;
        }

        #region INotifyPropertyChanged Members
        [field: NonSerialized]
        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(PropertyChangedEventArgs e)
        {
            var handler = this.PropertyChanged;
            if (handler != null)
            {
                handler(this, e);
            }
        }

        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (this.PropertyChanged != null)
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
        #endregion // INotifyPropertyChanged Members

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            shardedDoc();
        }


    }
}

<Window x:Class="SharePoint2013.SP_List_Treeview"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:spc="clr-namespace:Microsoft.SharePoint.Client;assembly=Microsoft.SharePoint.Client"
        xmlns:local="clr-namespace:SharePoint2013" 
        Title="SP_List_Treeview" Height="300" Width="300"><StackPanel><Button Click="Button_Click" Content="Load"/><TreeView ItemsSource="{Binding Path=lists}"><TreeView.Resources><HierarchicalDataTemplate
					DataType="{x:Type spc:List}" ><TextBox Text="{Binding Title}" /></HierarchicalDataTemplate><HierarchicalDataTemplate
                            DataType="{x:Type spc:FolderCollection}"
                            ItemsSource="{Binding Path=RootFolder.Folders}"><TextBox Text="a{Binding Path=Name}" /></HierarchicalDataTemplate></TreeView.Resources></TreeView></StackPanel></Window>