1. 系统默认菜单栏

创建项目后运行，默认的样子

image.png

2. 自定义菜单栏

通常情况下系统默认的菜单栏无法满足项目需求，例如需要添加一个特殊的菜单项，或者删除默认菜单中的菜单项等等。

通过在AppDelegate中重写buildMenu(with builder: UIMenuBuilder)方法实现自定义菜单栏

#if targetEnvironment(macCatalyst)
extension AppDelegate {
    
    override func buildMenu(with builder: UIMenuBuilder) {
        ...
    }
}
#endif

2.1 删除默认菜单栏

        //  删除文件菜单
        builder.remove(menu: .file)
        //  删除编辑菜单
        builder.remove(menu: .edit)
        //  删除应用菜单下的服务菜单
        builder.remove(menu: .services)

运行结果

image.png

2.2 往默认菜单栏中插入菜单

        let keyMenu = UIMenu(title: "键盘按键", options: .displayInline, children: [
            UIKeyCommand(title: "1",
                         action: #selector(command1Action),
                         input: "1",
                         modifierFlags: .command),
            UIKeyCommand(title: "P",
                         action: #selector(commandAndShiftPAction),
                         input: "P",
                         modifierFlags: [.command, .shift])
        ])
        builder.insertChild(keyMenu, atStartOfMenu: .window)

...

@objc private func command1Action() {
    print("command + 1")
}
    
@objc private func commandAndShiftPAction() {
    print("command + shift + P")
}

运行结果

image.png

2.3 新增菜单

        let newWindowMenu = UIMenu(title: "新窗口", options: .destructive, children: [
            UICommand(title: "缩放", action: #selector(scaleAction)),
            UIKeyCommand(title: "关闭", action: #selector(closeAction), input: "W", modifierFlags: .command)
        ])
        builder.insertSibling(newWindowMenu, afterMenu: .application)

...
@objc private func scaleAction() {
    print("缩放")
}
    
@objc private func closeAction() {
    print("关闭")
}

运行结果