절차

1. 프로젝트 작성

2. "Main.storyboard" 삭제

3. 「Info.plist」의 「Main storyboard file base name」을 「Main」→없음

4. AppDelegate.swift에 뷰 정의

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    self.window = UIWindow(frame: UIScreen.main.bounds)
    self.window?.rootViewController = ViewController()
    self.window?.makeKeyAndVisible()

    return true
}

override func viewDidLoad() {
    super.viewDidLoad()
    self.view.backgroundColor = UIColor.red // 背景を赤に
}

완성