Ios 如何使用Swift将自定义上下文菜单项添加到UITextView？

我成功地将UITextView子类化，并禁用了“定义”上下文菜单项

class TextViewer: UITextView {

   // Overide, disable the "Define" contextual menu item
   override func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool     {
       if action == "_define:" {
           return false;
       }
       return super.canPerformAction(action, withSender: sender)
   }

}

但是现在，我如何添加一个不同的/自定义的菜单项来代替它呢？我猜可能是这样的，但不太对

var menuController = UIMenuController.sharedMenuController()
var customMenuItem = UIMenuItem(title: "Lookup", action: "lookupWord")
menuController.menuItems?.append(customMenuItem)

谢谢你们能给我的任何帮助

Nevermind：

let mnuController = UIMenuController.sharedMenuController()
let lookupMenu = UIMenuItem(title: "Tshawb", action: "tshawb")
mnuController.menuItems = NSArray(array: [lookupMenu])

// This makes the menu item visible.
mnuController.setMenuVisible(true, animated: true)