【ANDROID STUDIO】 Options Menu

package com.example.optionmemu;

import androidx.appcompat.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);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.menu_settings) {
            Toast.makeText(this, "Settings", Toast.LENGTH_LONG).show();
        } else {
            return super.onContextItemSelected(item);
        }
        return true;
    }
}

<?xml version="1.0" encoding="utf-8"?>
    <menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item android:id="@+id/menu_settings"
    android:title="@string/menu_settings"
    app:showAsAction="never">
        <menu>
            <item android:id="@+id/menu_sub1"
            android:title="Storage Settings" />
            <item android:id="@+id/menu_sub2"
            android:title="Screen Settings" />
            </menu>
        </item>
    </menu>