如何在Mac中启用NSMenuItems？

import Cocoa

class AppDelegate: NSObject, NSApplicationDelegate {
    let statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)
    let menu = NSMenu()

    func applicationDidFinishLaunching(_ aNotification: Notification) {
        // 创建菜单项
        let menuItem1 = NSMenuItem(title: "菜单项1", action: #selector(menuItemClicked(_:)), keyEquivalent: "")
        let menuItem2 = NSMenuItem(title: "菜单项2", action: #selector(menuItemClicked(_:)), keyEquivalent: "")
        
        // 将菜单项添加到菜单中
        menu.addItem(menuItem1)
        menu.addItem(menuItem2)
        
        // 设置菜单
        statusItem.menu = menu
    }
    
    @objc func menuItemClicked(_ sender: NSMenuItem) {
        // 处理菜单项点击事件
        if sender.title == "菜单项1" {
            // 执行菜单项1的操作
        } else if sender.title == "菜单项2" {
            // 执行菜单项2的操作
        }
    }
}

let appDelegate = AppDelegate()
NSApplication.shared.delegate = appDelegate
NSApplication.shared.run()