public DetailsView() { lastDirection = ListSortDirection.Ascending; lastHeaderClicked = null; RealizedItems = new SuppressableObservableCollection <FileInfoWrapper>(); RealizedItems.SuppressChanged = true; InitializeComponent(); DetailsListView.AddHandler(Thumb.DragDeltaEvent, new DragDeltaEventHandler(Thumb_DragDelta), true); headerTemplateArrowUp = Resources["HeaderTemplateArrowUp"] as DataTemplate; headerTemplateArrowDown = Resources["HeaderTemplateArrowDown"] as DataTemplate; }