Cocoa-以编程方式添加菜单项

如何以编程方式在子菜单中添加菜单项？

使用等，例如：

NSMenu *subMenu = ...;
NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:@"foo" 
                    action:@selector(fooClicked:) keyEquivalent:@""]; 
[item autorelease];
[item setTarget:self];
[subMenu addItem:item];

斯威夫特5

let subMenu = NSMenu()
let menuItem = NSMenuItem(
    title: "Menu item title",
    action: #selector(menuItemClicked(_:)),
    keyEquivalent: ""
)
menuItem.target = self
menuItem.toolTip = "Menu item tooltip"
subMenu.addItem(menuItem)