public void LoadCheckedPaths(List <string> checkedPaths) { if (fCheckBox.IsChecked == true) { checkedPaths.Add(fFullPath); return; } else { foreach (object item in Items) { FolderTreeViewItem tvm = item as FolderTreeViewItem; if (tvm != null) { tvm.LoadCheckedPaths(checkedPaths); } } } }