【Swift】デバイスの向き変更を検知/取得する方法！UIDeviceOrientation型

var orientation: UIDeviceOrientation

UIDevice.current.orientation

func printOrientation(){
    
    let orientation:UIDeviceOrientation = UIDevice.current.orientation
    switch orientation{
        case .unknown:
            print("デバイスの向きが不明")
        case .portrait:
            print("デバイスの向きが縦向き")
        case .portraitUpsideDown:
            print("デバイスの向きが逆さま")
        case .landscapeLeft:
            print("デバイスの向きが左向き")
        case .landscapeRight:
            print("デバイスの向きが右向き")
        case .faceUp:
            print("デバイスが水平で画面が上向き")
        case .faceDown:
            print("デバイスが水平で画面が下向き")
        default:
            break       
    }
}

func observerOrientation(){
    NotificationCenter.default.addObserver(
        forName: UIDevice.orientationDidChangeNotification,
        object: nil,
        queue: nil) { orientation in
             print(type(of: orientation)) // Notification
            print("デバイスの向きが変わったよ")
        }
}

func observerOrientation(){
    UIDevice.current.beginGeneratingDeviceOrientationNotifications()
    NotificationCenter.default.addObserver(
        forName: UIDevice.orientationDidChangeNotification,
        object: nil,
        queue: nil) { orientation in
            print(type(of: orientation)) // Notification
            print("デバイスの向きが変わったよ")
        }
}

func stopObserver(){
    UIDevice.current.endGeneratingDeviceOrientationNotifications()
}

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)
    
    coordinator.animate(alongsideTransition: { (context) in
        // iOS12以前
        // let newOrientation = UIApplication.shared.statusBarOrientation
        // iOS13以降
        guard let newOrientation = self.view.window?.windowScene!.interfaceOrientation else { return }
        
        if newOrientation.isLandscape {
            print("横向き")
        } else if newOrientation.isPortrait {
            print("縦向き")
        }
    }) { (context) in
        // 画面の向きが変わった後の処理をここに追加
    }
}