问当ListFragment为空时，SetEmptyText()不会出现

EN

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);

    new getData().execute();
}

private class getData extends AsyncTask<Void, Void, ArrayList<Object>> {

    @Override
    protected ArrayList<Object> doInBackground(Void... params) {
        // TODO Auto-generated method stub
        try {
            artists = new ArrayList<Object>();
            artists = loadArtists("taqwa.xml");
            return loadXml("taqwa.xml");
        } catch (XmlPullParserException e) {
            e.printStackTrace();

            Utils.log("XML exception", "true");
            return null;
        } catch (IOException e) {
            e.printStackTrace();

            Utils.log("IOException", "true");

            return null;
        }
    }

    @Override
    protected void onPostExecute(ArrayList<Object> result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);

        if (result != null) {
            ListAdapter ladapter = new ListAdapter(getActivity(),
                    R.layout.list_row, null, artists, 3);
            setListAdapter(ladapter);
        } else {
            setEmptyText("not found wallahi!");
        }

    }

}