android 子菜单

<!-- 定义基础布局LinearLayout -->
<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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical">
    <!-- 定义TextView控件 -->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="请点击物理菜单键显示菜单，再次点击菜单选项显示子菜单"
        />
</LinearLayout>

package com.example.yanlei.yl2;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.Toast;

//导入必备的包



public class MainActivity extends AppCompatActivity {

    //定义Menu中每个菜单选项的Id
    final int Menu_1 = Menu.FIRST;
    final int Menu_2 = Menu.FIRST + 1;
    final int Menu_3 = Menu.FIRST + 2;
    final int Menu_4 = Menu.FIRST + 3;
    final int Menu_5 = Menu.FIRST + 4;
    final int Menu_6 = Menu.FIRST + 5;
    final int Menu_7 = Menu.FIRST + 6;
    final int Menu_8 = Menu.FIRST + 7;
    final int Menu_9 = Menu.FIRST + 8;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); // 调用父类的onCreate方法
        // 通过setContentView方法设置当前页面的布局文件为activity_main
        setContentView(R.layout.activity_main);
    }

    //创建Menu菜单的回调方法
    public boolean onCreateOptionsMenu(Menu m) {
        //定义子菜单，然后添加到Menu中
        SubMenu fileMenu = m.addSubMenu("新建");
        //在菜单选项的子菜单中添加选项内容
        //add方法的参数：add(分组id,itemid, 排序, 菜单文字)
        fileMenu.add(0, Menu_1, 0, "文件1");
        fileMenu.add(0, Menu_2, 0, "文件2");
        fileMenu.add(0, Menu_3, 0, "文件3");

        SubMenu openMenu = m.addSubMenu("打开");
        //在菜单选项的子菜单中添加选项内容
        //add方法的参数：add(分组id,itemid, 排序, 菜单文字)
        openMenu.add(0, Menu_4, 0, "文件4");
        openMenu.add(0, Menu_5, 0, "文件5");
        openMenu.add(0, Menu_6, 0, "文件6");

        SubMenu saveMenu = m.addSubMenu("保存");

        //在菜单选项的子菜单中添加选项内容
        //add方法的参数：add(分组id,itemid, 排序, 菜单文字)
        saveMenu.add(0, Menu_7, 0, "文件7");
        saveMenu.add(0, Menu_8, 0, "文件8");
        saveMenu.add(0, Menu_9, 0, "文件9");
        return super.onCreateOptionsMenu(m);
    }

    //Menu菜单选项的选项选择的回调事件
    public boolean onOptionsItemSelected(MenuItem item) {
        //参数为用户选择的菜单选项对象
        //根据菜单选项的id来执行相应的功能
        switch (item.getItemId()) {
            case 1:
                Toast.makeText(this, "新建文件1", Toast.LENGTH_SHORT).show();
                break;
            case 2:
                Toast.makeText(this, "新建文件2", Toast.LENGTH_SHORT).show();
                break;
            case 3:
                Toast.makeText(this, "新建文件3", Toast.LENGTH_SHORT).show();
                break;
            case 4:
                Toast.makeText(this, "打开文件4", Toast.LENGTH_SHORT).show();
                break;
            case 5:
                Toast.makeText(this, "打开文件5", Toast.LENGTH_SHORT).show();
                break;
            case 6:
                Toast.makeText(this, "打开文件6", Toast.LENGTH_SHORT).show();
                break;
            case 7:
                Toast.makeText(this, "保存文件7", Toast.LENGTH_SHORT).show();
                break;
            case 8:
                Toast.makeText(this, "保存文件8", Toast.LENGTH_SHORT).show();
                break;
            case 9:
                Toast.makeText(this, "保存文件9", Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onOptionsItemSelected(item);
    }
}