activity fargment class

17_activity_fragment.java

@Override
public void onCreate (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sample);

    FragmentManager manager = getFragmentManager();
    FragmentTransaction transaction = manager.beginTransaction();

    transaction.add(R.id.activity_container, new FragmentSample1());
    transaction.commit();
}