import UIKit
import MKQRScanner

class ViewController: UIViewController {
    @IBOutlet weak var infoLbl: UILabel!

    var scanner: MKQRScanner?
    override func viewDidLoad() {
        super.viewDidLoad()
    }
    
    @IBAction func scanTapped(_ sender: Any) {
        scanner = MKQRScanner(navigationController: navigationController, delegate: self)
        scanner?.start()
    }
}

extension ViewController: MKQRScannerDelegate {
    func scanFailed(error: Error) {
        print(#function)
        print(error)
    }

    func scanSuccessful(result: String) {
        print(result)
        infoLbl.text = result
    }
    
    func scanCanceled() {
        print(#function)
        infoLbl.text = "Scan canceled"
    }   
}