Android studio实现菜单效果

package com.example.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    //用onCreateOptionsMenu（）显示菜单
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu,menu);//getMenuInflater()方法得到MenuInflater
        //调用inflate接收两个参数
        //R.menu.main指调用menu文件下的main资源文件
        return true;//返回true，允许创建的菜单显示,返回false不显示
    }
    //定义菜单响应事件
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){   //item.getItemId()判断我们选择那个菜单项
            case R.id.first:
                Toast.makeText(this, "FIRST", Toast.LENGTH_SHORT).show();
                break;
            case R.id.second:
                Toast.makeText(this, "SECOND", Toast.LENGTH_SHORT).show();
                break;
                default:
        }
        return true;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="Http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/add_item"
        android:title="ADD">
    </item>
    <item
        android:id="@+id/add_remove"
        android:title="REMOVE">
    </item>
</menu>

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
    android:id="@+id/f1"
    android:title="更换背景">
</item>
<item
    android:id="@+id/f2"
    android:title="参数设置">
    <menu>
        <group
            android:id="@+id/group1"
            android:checkableBehavior="all">
            <item
                android:id="@+id/s1"
                android:title="参数1">
            </item>
            <item
                android:id="@+id/s2"
                android:title="参数2">
            </item>
        </group>
    </menu>
</item>
<item
    android:id="@+id/f3"
    android:title="恢复出厂">
</item>
</menu>

package com.example.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    //用onCreateOptionsMenu（）显示菜单
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater=new MenuInflater(this);//实例化一个MenuInflater对象
        inflater.inflate(R.menu.menu,menu);//解析菜单文件
        return true;
    }
    //定义菜单响应事件
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if(item.getItemId()==R.id.f1)
            Toast.makeText(this, "更换背景", Toast.LENGTH_SHORT).show();
        else if(item.getItemId()==R.id.f3)
            Toast.makeText(this, "恢复出厂", Toast.LENGTH_SHORT).show();
        else
        {
            if(item.getGroupId()==R.id.group1){ //判断是否选中了第一层第二项
                //与menu.xml文件对应 android:checkableBehavior="all"
                if(item.isChecked()) //菜单被选中
                    item.setChecked(false);//设置菜单项不被选中
                else
                    item.setChecked(true);//设置菜单项被选中
            }
        }
        return true;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <TextView
        android:id="@+id/text1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="打开菜单："/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
    android:id="@+id/red"
    android:title="红色">
</item>
<item
    android:id="@+id/green"
    android:title="绿色">
</item>
<item
    android:id="@+id/blue"
    android:title="蓝色">
</item>

</menu>

package com.example.myapplication;

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
    private TextView tv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv=(TextView)findViewById(R.id.text1);
        reGISterForContextMenu(tv);//为文本注册上下文菜单
    }
    //用onCreateContextMenu（）显示菜单
    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        MenuInflater inflater=new MenuInflater(this);//实例化MenuInflater一个对象
        inflater.inflate(R.menu.menu,menu);//解析菜单文件
        menu.setHeaderTitle("选择颜色：");//为菜单头设置标题
    }
    @Override
    public boolean onContextItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case R.id.red:
                tv.setTextColor(Color.rgb(255,0,0));
                break;
            case R.id.green:
                tv.setTextColor(Color.rgb(0,255,0));
                break;
            default:
                tv.setTextColor(Color.rgb(0,0,255));
        }
        return true;
    }
}