How to assign DataSourceProperty to a Cell in a TreeList

Hello Uwe,
I have debugged a modified version of the E443 example, and found that the DataSourceProperty doesn't work because the TreeListEditor doesn't set the active IGridInplaceEdit editor, which is used by the LookupEditorHelper class when creating a lookup ListView.
This functionality will be supported once inplace editng is supported by our tree list editors: Tree List Editors - How to edit data directly in the tree view (inplace / inline modifications).
I have made the necessary modifications to the E443 example, and now your scenario is also supported:

C#
using System;  
using DevExpress.ExpressApp;  
using DevExpress.ExpressApp.TreeListEditors.Win;  
using DevExpress.ExpressApp.Win.Controls;  
using DevExpress.XtraTreeList;  
using DevExpress.XtraEditors.Repository;  
using DevExpress.Persistent.Base;  
using DevExpress.Xpo;  
using DevExpress.ExpressApp.Win.Core;  

namespace WinSolution.Module.Win {  
    public class TreeListInplaceEditViewController : ViewController<ListView> {  
        private ObjectTreeList treeList;  
        protected override void OnViewControlsCreated() {  
            base.OnViewControlsCreated();  
            TreeListEditor treeListEditor = View.Editor as TreeListEditor;  
            if (treeListEditor != null) {  
                treeList = (ObjectTreeList)treeListEditor.TreeList;  
                foreach (RepositoryItem ri in treeList.RepositoryItems)  
                    ri.ReadOnly = false;  
                treeList.CellValueChanged += treeList_CellValueChanged;  
                treeList.ShownEditor += treeList_ShownEditor;  
                treeList.OptionsBehavior.Editable = true;  
                treeList.OptionsView.EnableAppearanceEvenRow = true;  
                treeList.OptionsView.EnableAppearanceOddRow = true;  
                treeList.OptionsBehavior.ImmediateEditor = false;  
            }  
        }  
        protected override void OnDeactivating() {  
            if (treeList != null) {  
                treeList.CellValueChanged -= treeList_CellValueChanged;  
                treeList.ShownEditor -= treeList_ShownEditor;  
            }  
            base.OnDeactivating();  
        }  
        private void treeList_ShownEditor(object sender, EventArgs e) {  
            IGridInplaceEdit activeEditor = treeList.ActiveEditor as IGridInplaceEdit;  
            if (activeEditor != null && treeList.FocusedObject is IXPSimpleObject) {  
                activeEditor.GridEditingObject = treeList.FocusedObject;  
            }  
        }  
        private void treeList_CellValueChanged(object sender, CellValueChangedEventArgs e) {  
            object newValue = e.Value;  
            if (e.Value is IXPSimpleObject)  
                newValue = ObjectSpace.GetObject(e.Value);  
            ReflectionHelper.SetMemberValue(treeList.FocusedObject, e.Column.FieldName, newValue);  
            ObjectSpace.CommitChanges();  
        }  
    }  
}  

Let me know in case of any further difficulty.
Thanks,
Dennis