TreeView Node rekursiv über String suchen

/// <summary->
/// sucht TreeNode rekursiv
/// </summary->
/// <param name=&quot;n&quot;->StartNode</param->
/// <param name=&quot;txt&quot;->Suchtext</param->
/// <returns->gefundene TreeNode oder null</returns->
public TreeNode FindNode(TreeNode n, string txt)
{
    TreeNode r = null;

    foreach (TreeNode tn in n.Nodes)
    {
        if (tn.Text == txt)
        {
            r = tn;
            break;
        }

        r = FindNode(tn, txt);

        if (r != null) break;
    }

    return r;
}