MFC Tree Control: How to expand/collapse a branch?

Q: How to expand/collapse a branch?

A: If you want to expand or collapse one only item use

Code:

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m_tree.Expand(hItem, TVE_EXPAND); // or 'TVE_COLLAPSE'

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If you want to expand or collapse an item and all of its children use something like this:

Code:

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void ExpandTreeItem(const CTreeCtrl &tree, HTREEITEM hItem, UINT nCode)
{
  HTREEITEM hChild;
 
  if(tree.ItemHasChildren(hItem))
  {
    tree.Expand(hItem, nCode);
    hChild = tree.GetChildItem(hItem);
   
    while(hChild)
    {
      ExpandTreeItem(tree, hChild, nCode);
      hChild = tree.GetNextItem(hChild, TVGN_NEXT);
    }
  }
}

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