Android studio实现菜单操作

<?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">
    <TextView
        android:id="@+id/text1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="长时间点这"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/open"
        android:title="打开">
    </item>
    <item
        android:id="@+id/close"
        android:title="关闭">
    </item>
    <item
        android:id="@+id/quit"
        android:title="退出">
    </item>
</menu>

package com.example.first;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private static final  String TAG="MainActivity";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView tv=(TextView)findViewById(R.id.text1);
        registerForContextMenu(tv);
    }
    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);
        MenuInflater inflater=new MenuInflater(this);
        inflater.inflate(R.menu.menu,menu);
        menu.setHeaderTitle("选择：");//为菜单头设置标题
    }
    @Override
    public boolean onContextItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case R.id.open:
                Log.i(TAG, "已经打开");
                break;
            case R.id.close:
                Log.i(TAG, "已经关闭");
                break;
            case R.id.quit:
                Toast.makeText(this, "已经退出", Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onContextItemSelected(item);
    }
}

package com.example.first;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
import android.util.Log;
public class MainActivity extends AppCompatActivity {
    private static final  String TAG="MainActivity";
    @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()){
            case R.id.open:
                Log.i(TAG, "已经打开");
                break;
            case R.id.close:
                Log.i(TAG, "已经关闭");
                break;
            case R.id.quit:
                Toast.makeText(this, "已经退出", Toast.LENGTH_SHORT).show();
                break;
        }
        return true;
    }
}