private void _treeView_Expanded(object sender, RoutedEventArgs e)
{
var treeViewItem = e.OriginalSource as TreeViewItem;
if (treeViewItem == null) return;
var treeViewModel = (TreeViewModelBase)_treeView.SearchItemFromElement((DependencyObject)treeViewItem);
var path = new Route();
foreach (var item in treeViewModel.GetAncestors())
{
if (item is SignatureTreeViewModel) path.Add(((SignatureTreeViewModel)item).Value.LinkItem.Signature);
}
Settings.Instance.LinkControl_ExpandedPaths.Add(path);
}