Icke fungerande QR-kodscanner

import Foundation
import AVFoundation

@objc(CodeScannerViewManager)
class CodeScannerViewManager: RCTViewManager {

  @objc
  override func view() -> UIView! {
    let captureView = CodeScannerViewController()
    return captureView.view
  }

  @objc
  override static func requiresMainQueueSetup() -> Bool {
    return true
  }

}

@objc(CodeScannerViewController)
class CodeScannerViewController: UIViewController {

  var captureSession = AVCaptureSession()
  var videoPreviewLayer: AVCaptureVideoPreviewLayer?

  @objc
  override func viewDidLoad() {
    super.viewDidLoad()

    print("viewDidLoad")

    let discoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera], mediaType: .video, position: .back)

    guard let captureDevice = discoverySession.devices.first else {
        print("No device found")
        return
    }

    do {
        let input = try AVCaptureDeviceInput(device: captureDevice)
        captureSession.addInput(input)

        let videoMetaDataOutput = AVCaptureMetadataOutput()
        captureSession.addOutput(videoMetaDataOutput)

        videoMetaDataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)

        videoMetaDataOutput.metadataObjectTypes = [.qr]

        videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        videoPreviewLayer?.videoGravity = .resizeAspectFill
        videoPreviewLayer?.frame = view.layer.bounds

        view.layer.addSublayer(videoPreviewLayer!)

        captureSession.startRunning()

        print("all done!")

    } catch {
        print(error)
        return
    }

  }


//
//  override func viewWillAppear(_ animated: Bool) {
//    super.viewWillAppear(animated)
//
//    if (session?.isRunning == false) {
//      DispatchQueue.global(qos: .userInitiated).async {
//        self.session.startRunning()
//      }
//    }
//  }
//
//  override func viewWillDisappear(_ animated: Bool) {
//    super.viewWillDisappear(animated)
//
//    if (session?.isRunning == true) {
//      DispatchQueue.global(qos: .userInitiated).async {
//        self.session.stopRunning()
//      }
//    }
//  }
//
//  override var prefersStatusBarHidden: Bool {
//    return true
//  }
//
//  override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
//    return .portrait
//  }
//
//  override func viewDidAppear(_ animated: Bool) {
//    super.viewDidAppear(animated)
//    DispatchQueue.global(qos: .userInitiated).async {
//      self.session.startRunning()
//    }
//  }
//
//  override func viewDidDisappear(_ animated: Bool) {
//    super.viewWillDisappear(animated)
//    DispatchQueue.global(qos: .userInitiated).async {
//      self.session.stopRunning()
//    }
//  }
}

@objc
extension CodeScannerViewController: AVCaptureMetadataOutputObjectsDelegate {
  @objc
  func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
    print("Count: \(metadataObjects.count)")
  }
}