无Storyboard/Xib纯代码开发：如何给NSMenuItem添加子视图？

要在纯代码实现的菜单栏应用中给NSMenuItem添加自定义视图（灰色说明文本+自定义按钮），可以通过NSMenuItem的view属性绑定自定义NSView来实现，具体步骤如下：

1. 创建包含文本和按钮的自定义视图类 #

定义一个继承自NSView的子类，将灰色文本标签和自定义按钮整合进去：

class CustomMenuItemView: NSView {
    // 灰色说明文本标签
    private let descriptionLabel: NSTextField = {
        let label = NSTextField()
        label.stringValue = "这是一行灰色说明文本"
        label.textColor = NSColor.gray
        label.isEditable = false
        label.isBordered = false
        label.backgroundColor = .clear
        label.alignment = .left
        return label
    }()
    
    // 自定义按钮
    private let customButton: NSButton = {
        let button = NSButton(title: "自定义按钮", target: nil, action: #selector(customButtonTapped))
        button.bezelStyle = .rounded
        button.controlSize = .small
        return button
    }()
    
    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        setupView()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    private func setupView() {
        // 添加子视图
        addSubview(descriptionLabel)
        addSubview(customButton)
        
        // 禁用自动约束转换，启用Auto Layout
        descriptionLabel.translatesAutoresizingMaskIntoConstraints = false
        customButton.translatesAutoresizingMaskIntoConstraints = false
        
        // 设置布局约束：文本左对齐、按钮右对齐，二者垂直居中，视图高度适配内容
        NSLayoutConstraint.activate([
            descriptionLabel.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 16),
            descriptionLabel.centerYAnchor.constraint(equalTo: centerYAnchor),
            
            customButton.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -16),
            customButton.centerYAnchor.constraint(equalTo: centerYAnchor),
            
            heightAnchor.constraint(greaterThanOrEqualToConstant: 32),
            descriptionLabel.trailingAnchor.constraint(lessThanOrEqualTo: customButton.leadingAnchor, constant: -8)
        ])
    }
    
    @objc private func customButtonTapped() {
        // 按钮点击逻辑，可按需修改
        print("自定义按钮被点击")
    }
}

2. 在菜单初始化方法中添加自定义菜单项 #

修改你的setupMenus方法，新增一个绑定了自定义视图的NSMenuItem：

func setupMenus() {
    let menu = NSMenu()

    let one = NSMenuItem(title: "Toggle", action: #selector(didTapOne), keyEquivalent: "1")
    menu.addItem(one)
    
    let warning = NSMenuItem(title: "INSTRUCTIONS", action: #selector(didTapWarning), keyEquivalent: "")
    menu.addItem(warning)
    
    // 添加带自定义视图的菜单项
    let customMenuItem = NSMenuItem()
    // 设置视图尺寸，宽度建议固定值避免菜单栏异常，高度可自适应
    customMenuItem.view = CustomMenuItemView(frame: NSRect(x: 0, y: 0, width: 250, height: 32))
    menu.addItem(customMenuItem)
    
    menu.addItem(NSMenuItem.separator())
    
    menu.addItem(NSMenuItem(title: "Quit", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q"))
    
    // 将菜单绑定到状态栏项
    statusItem?.menu = menu
}

3. 关键注意点 #

• 自定义视图的宽度建议设置固定值（如250），防止菜单栏宽度出现异常；高度可通过Auto Layout自适应内容。
• 若需将按钮点击事件绑定到外部逻辑，可在创建CustomMenuItemView时传入target/action，或通过闭包回调实现。
• 确保在applicationDidFinishLaunching中调用setupMenus()，完成菜单与状态栏项的绑定。

内容的提问来源于stack exchange，提问作者Mansidak