Update activity from AlertDialog [closed]

Whenever I click on the Toolbar I have a menu that when I click on one of the options I get a AlertDialog . This AlertDialog has a setSingleChoiceItems , in which the user when choosing an option and clicking OK, this option is saved in the DB. All of this works well. The problem is that when I go back to the activity I want different information to appear depending on the user's choice in AlertDialog and I'm not getting it.

I'm using OnResume ()

    mes = (TextView) findViewById(R.id.textMes);
    metaDef = (TextView) findViewById(R.id.textMetaDef);
    despesa = (TextView) findViewById(R.id.textDesp);

    if (db_helper.hasMoeda()) {
        moeda = db_helper.getMoeda();
    } else {
        db_helper.updateMoeda("Euro");
    }

    Gasto gasto=new Gasto();
    gasto=db_helper.getGasto();

    mes.setText(gasto.getMes());

    if (moeda.equalsIgnoreCase("Euro")) {
        metaDef.setText("" + gasto.getMeta() + " €");
        despesa.setText(String.format("%.2f €", gasto.getDespesa_final()));
    } else if (moeda.equalsIgnoreCase("Real")) {
        metaDef.setText("R$ " + gasto.getMeta());
        despesa.setText(String.format("R$ %.2f", gasto.getDespesa_final()));

    }

What is happening is that the activity does not update when I click on alertDialog OK. Anyone have any suggestions?