TreeView 검색(재귀호출)

//TreeView의 검색
        public TreeNode SearchNode(TreeNodeCollection aNodes, string strKey)
        {
            foreach ( TreeNode node in aNodes )
            {
                if ( node.Text.Contains(strKey)  )
                    return node;
                TreeNode findNode = SearchNode(node.Nodes, strKey);
                if ( findNode != null )
                    return findNode;
            }
            return null;
        }