Android的ActionBar菜单运用

<menu xmlns:android="http://schemas.android.com/apk/res/android" >	<item        android:id="@+id/menu_settings"        android:orderInCategory="100"        android:showAsAction="always"        android:title="@string/menu_settings" />    <item        android:id="@+id/menu_settingss"        android:orderInCategory="100"        android:showAsAction="always"        android:icon="@android:drawable/ic_menu_sort_by_size">        <menu>            <item android:id="@+id/action_sort_size"                  android:icon="@android:drawable/ic_menu_sort_by_size"                  android:title="action_bar_sort_size"/>            <item android:id="@+id/action_sort_alpha"                  android:icon="@android:drawable/ic_menu_sort_alphabetically"                  android:title="action_bar_sort_alpha"/>        </menu>   	</item>	</menu>

package com.example.actionbartab;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.MenuInflater;public class MainActivity extends Activity {	@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);	}	@Override	public boolean onCreateOptionsMenu(Menu menu) {		// Inflate the menu; this adds items to the action bar if it is present.		MenuInflater inflater = getMenuInflater();          inflater.inflate(R.menu.activity_main, menu);		return true;	}}