Android学习笔记之Menu的ShowAsAction属性的设立

（1）在res--menu目录下的main.xml文件

<menu xmlns:android="http://schemas.android.com/apk/res/android" >    <item        android:id="@+id/file"        android:orderInCategory="100"        android:showAsAction="always"        android:title="文件(F)">        <menu>            <item                android:id="@+id/create"                android:title="新建">            </item>            <item                android:id="@+id/open"                android:title="打开">            </item>        </menu>    </item>    <item        android:id="@+id/edit"        android:orderInCategory="100"        android:showAsAction="always"        android:title="编辑(E)">        <menu>            <item                android:id="@+id/create1"                android:title="新建">            </item>            <item                android:id="@+id/open1"                android:title="打开">            </item>        </menu>    </item>    <item        android:id="@+id/format"        android:orderInCategory="100"        android:showAsAction="always"        android:title="格式(O)">        <menu>            <item                android:id="@+id/create2"                android:title="新建">            </item>            <item                android:id="@+id/open2"                android:title="打开">            </item>        </menu>    </item></menu>

package com.example.menu_showasaction;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.MenuItem;import android.widget.Toast;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.		getMenuInflater().inflate(R.menu.main, menu);		return true;	}	@Override	public boolean onMenuItemSelected(int featureId, MenuItem item) {		switch (item.getItemId()) {		case R.id.create:			Toast.makeText(MainActivity.this, "create...", Toast.LENGTH_SHORT);			break;		default:			break;		}		return super.onMenuItemSelected(featureId, item);	}}