public void ListBox_ItemCopiedToDataContext3 () { bool realized; ListBox box = new ListBox (); box.ItemsPanel = CreateVirtualizingPanel (); CreateAsyncTest (box, () => { box.Items.Add (new Rectangle ()); }, () => { ListBoxItem container; var panel = box.FindFirstChild<CustomVirtualizingPanel> (); using (panel.ItemContainerGenerator.StartAt (new GeneratorPosition (-1, 1), GeneratorDirection.Forward, true)) container = (ListBoxItem) panel.ItemContainerGenerator.GenerateNext (out realized); Assert.IsNotNull (container, "#1"); IGenerator.PrepareItemContainer (container); Assert.AreEqual (box.Items [0], container.Content, "#2"); } ); }