Android菜单应用（Menu）

整体运行效果如下图：

具体实现：

1、创建过程，工程名为Menu

2、在工程目录“res/menu”目录下创建一个名为menu.xml的文件，内容如下：

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:id="@+id/help"
        android:title="帮助"/>"
    <item
        android:id="@+id/our"
        android:title="联系我们"/>
</menu>

3、编写MainActivity.java的文件。具体代码如下：

package com.example.menu;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;

public class MainActivity extends Activity {

    final int ok=1;
    final int cancle=2;
    final int about=3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        if (savedInstanceState == null) {
            getFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment()).commit();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        menu.add(0,ok,0,"开始");
        menu.add(0,cancle,0,"取消");
        Menu file=menu.addSubMenu(0,about,0,"关于");
        
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu, file);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        switch(id){
        case ok:
            this.setTitle("开始");
            return true;
        case cancle:
            this.setTitle("取消");
            return true;
        case about:
            this.setTitle("关于");
            return true;
        case R.id.help:
            this.setTitle("帮助信息");
            return true;
        case R.id.our:
            this.setTitle("联系我们");
            return true;
        
        }

        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container,
                    false);
            
            
            return rootView;
        }
    }

}