template<typename T>
void FreeAllItemsData(_In_ HTREEITEM hItem)
{
	if (hItem == NULL)
		return;

	T* pData = (T*)m_Tree.GetItemData(hItem);
	if (pData)
	{
		delete pData;
		pData = NULL;
	}

	HTREEITEM hChild = m_Tree.GetChildItem(hItem);
	FreeAllItemsData<T>(hChild);

	HTREEITEM hNextSibling = m_Tree.GetNextSiblingItem(hItem);
	FreeAllItemsData<T>(hNextSibling);
}

void DeleteAllItems(_In_ HTREEITEM hItem)
{
    if (hItem == NULL)
        return;

    HTREEITEM hChild = m_Tree.GetChildItem(hItem);
    DeleteAllItems(hChild);

    HTREEITEM hNextSibling = m_Tree.GetNextSiblingItem(hItem);
    DeleteAllItems(hNextSibling);

	m_Tree.DeleteItem(hItem);
}