private void Note_LeftButtonDown(object sender, MouseButtonEventArgs e) { var BoxItem = (sender as ListBoxItem); var item = BoxItem.Content as Note; if (item.isActive) { return; } var notelist = CurrentTrack.GetNotesRef(item.Key, item.Direction); var index = CurrentTrack.GetNotesRef(item.Key, item.Direction).IndexOf(item); var newNote = new Note(item.Key, item.Direction) { Position = index, isActive = true }; notelist[index] = newNote; UpdateTitle(true); e.Handled = true; }