Crear un desplegable para Android y rellenarlo con un array

package com.oskratch.desplegable;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Spinner;

public class Desplegable extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Spinner spinner = (Spinner) findViewById(R.id.spinner1);
        ArrayAdapter<CharSequence> adaptador = ArrayAdapter.createFromResource(this, R.array.paises, android.R.layout.simple_spinner_item);
        adaptador.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adaptador);
    }
}