static void item_PreviewMouseMove(object sender, System.Windows.Input.MouseEventArgs e) { TimeSlider slider = (TimeSlider)sender; ContentAdorner popup = GetPopupAdorner(slider); if (popup == null) { popup = new ContentAdorner(slider); slider.SetValue(PopupAdornerProperty, popup); AdornerLayer layer = AdornerLayer.GetAdornerLayer((Visual)slider.Parent); layer.Add(popup); } popup.Visibility = Visibility.Visible; Track _track = slider.Template.FindName("PART_Track", slider) as Track; Point position = e.GetPosition(slider); popup.Content = _track.ValueFromPoint(position); position.Y = slider.ActualHeight / 2.0; popup.PlacementOffset = position; }