AppDelegate.swift Preview // //  AppDelegate.swift //  UIKit017 // import UIKit @UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate {          internal var window: UIWindow?          func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {      … Sigue leyendo UIBarButtonItemの (Swift3.0)