public InsertAdorner(TreeViewExItem treeViewItem, InsertContent content) : base(GetParentBorder(treeViewItem)) { this.treeViewItem = treeViewItem; layer = AdornerLayer.GetAdornerLayer(AdornedElement); layer.Add(this); contentPresenter = new ContentPresenter(); contentPresenter.HorizontalAlignment = HorizontalAlignment.Stretch; contentPresenter.Width = treeViewItem.ActualWidth; contentPresenter.Content = content; Binding b = new Binding("InsertTemplate"); b.Source = treeViewItem.ParentTreeView; b.Mode = BindingMode.OneWay; contentPresenter.SetBinding(ContentPresenter.ContentTemplateProperty, b); content.InsertionMarkerBrush = treeViewItem.ParentTreeView.InsertionMarkerBrush; content.Item = treeViewItem; }