How to find all nodes of a treeView?

Question

C++ / C#

Can't get all treeView nodes. When executing the following code, only the first node's Text is displayed endlessly:

private void Button_Click(object sender, EventArgs e)
{
    if (searchOnAll.Checked == true)
    {
        TreeNodeCollection nodes = themes.Nodes;
        foreach (TreeNode tn in nodes)
        {
            CallAllNodes(tn);
        }
    }
}
 
private void CallAllNodes(TreeNode node)
{
    MessageBox.Show(node.Text);
    foreach (TreeNode tn in themes.Nodes)
    {
        CallAllNodes(tn);
    }
}

Answer 1

foreach (TreeNode tn in node.Nodes)