;recursion call

void TraverseTree(std::wostream& output, HTREEITEM hItem) const {
    if (!hItem) return;

    auto text = GetItemText(hItem);
    
    hChild = TreeView_GetChild(hTreeView, hItem);
    while (hChild != 0) {
      TraverseTree(output, hChild);
      hChild = TreeView_GetNextSibling(hTreeView, hChild);
     }
}


main:
hRoot = TreeView_GetRoot(hTreeView);
      if (hRoot) {
        TraverseTree(file, hRoot);
      }