XML and Adapter

I reading a XML it's working ok and I have a Adaptar it's working ok. I'm trying that in the adapter reads the data of the XML.

Edit: The void onPostExecute reading the datas of XML ok but when I adapt the adapter within, the adapter not working. The adapter working ok in the function createData.

    @Override
    protected void onPostExecute(Void result) {

       ArrayList<datos_calendario> arraydir = new ArrayList<datos_calendario>();
        datos_calendario grupo;

        for(PostValue post : helper.posts) {
            // Results of XML
        );

        if (pd!=null) {
            if (pd.isShowing()) {
                pd.dismiss();
            }
        }

    }
public void createData() {

    // Adapter working ok
    for (int j = 0; j < 5; j++) {
        adapter_clase_group group = new adapter_clase_group("Test " + j);
        for (int i = 0; i < 5; i++) {
            group.children.add("Sub Item" + i);
        }
        groups.append(j, group);
    }

}