Android学习笔记之Menu的ShowAsAction属性的设置

（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);
	}

}