ActionBar的使用

在Android3.0以上的版本使用

在menu文件夹中的main.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:holo="http://schemas.android.com/apk/res-auto">
	<item 
	    android:id="@+id/action_menu1"
	    android:showAsAction="ifRoom|withText"
	    android:icon="@drawable/ic_launcher"
	    android:title=""/>
	<item 
	    android:id="@+id/action_menu2"
	    android:showAsAction="ifRoom|withText"
	    android:title="文件">
	    <menu >
	        <item 
	            android:id="@+id/menu2_menu1"
	            android:title="打开"/>
	        <item 
	            android:id="@+id/menu2_menu2"
	            android:title="关闭"/>
	    </menu>
	</item>
	<item 
	    android:id="@+id/action_menu3"
	    android:showAsAction="ifRoom|withText"
	    android:title="设置"/>
	<item 
	    android:id="@+id/action_menu4"
	    android:showAsAction="ifRoom|withText"
	    android:title="帮助"/>
	<item 
	    android:id="@+id/action_menu5"
	    android:showAsAction="ifRoom|withText"
	    android:title="格式"/>
</menu>

activity_min.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.menu.MainActivity" >

   	<Button 
   	    android:id="@+id/show"
   	    android:layout_width="wrap_content"
   	    android:layout_height="wrap_content"
   	    android:text="@string/show"/>
	<Button 
	    android:id="@+id/hide"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    android:text="@string/hide"/>
</LinearLayout>

MainActivity.java

package com.example.menu;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
	private Button btShow,btHide;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btShow=(Button) findViewById(R.id.show);
		btHide=(Button) findViewById(R.id.hide);
		btShow.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				MainActivity.this.getActionBar().show();
			}
		});
		btHide.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				MainActivity.this.getActionBar().hide();
			}
		});
	}
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// TODO Auto-generated method stub
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		// TODO Auto-generated method stub
		if (item.getItemId()==R.id.action_menu1) {
			Log.d("lhm", "点击了图标");
		}else if (item.getItemId()==R.id.action_menu2) {
			Log.d("lhm", "点击了文件");
		}else if (item.getItemId()==R.id.action_menu3) {
			Log.d("lhm", "点击了设置");
		}else if (item.getItemId()==R.id.action_menu4) {
			Log.d("lhm", "点击了帮助");
		}else if (item.getItemId()==R.id.action_menu5) {
			Log.d("lhm", "点击了格式");
		}else if (item.getItemId()==R.id.menu2_menu1) {
			Log.d("lhm", "点击了打开");
		}else if (item.getItemId()==R.id.menu2_menu2) {
			Log.d("lhm", "点击了关闭");
		}
		return super.onOptionsItemSelected(item);
	}

}