How to close Qr code scanner after scanned successfully - Swift 4

Question

I have integrated QR-code scanner and its working perfectly but the issue is not able to close the camera after scanned successfully. Here in my code, I want to close the camera if I tap confirm button... Please help me Thank you!!

@objc func scanButtonTapped(sender: UIButton) {
let session = AVCaptureSession()
    let captureDevice = AVCaptureDevice.default(for: .video)
    do {
        let input = try AVCaptureDeviceInput(device: captureDevice!)
        session.addInput(input)
    } catch {
        self.view.makeToast("Sorry Scanner is not working!")
    }

    let output = AVCaptureMetadataOutput()
    session.addOutput(output)
    output.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
    output.metadataObjectTypes = [AVMetadataObject.ObjectType.qr]
    video = AVCaptureVideoPreviewLayer(session: session)
    video.frame = view.layer.bounds
    view.layer.addSublayer(video)
    session.startRunning()
}

func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
    if metadataObjects != nil && metadataObjects.count != 0 {
        if let object = metadataObjects[0] as? AVMetadataMachineReadableCodeObject {
            if object.type == AVMetadataObject.ObjectType.qr {

                let alert = UIAlertController(title: "QR Code", message: object.stringValue, preferredStyle: .alert)
                alert.addAction(UIAlertAction(title:"Retake", style: .default, handler: nil))
                alert.addAction(UIAlertAction(title:"Confirm", style: .default, handler: { (nil) in
                    self.scannedCode = object.stringValue!
                }))
                present(alert, animated: true, completion: nil)
            }
        }
    }
}

Answer 1

First, you'll need to save your session object as an instance variable in your controller. For instance,

var session: AVCaptureSession?

Then instantiate your session when you need to use the camera

self.session = AVCaptureSession()

Then you can reference is from your metadataOutput method.

self.session.stopRunning()

Answer 2

Replace the Confirm Action by below given code :

alert.addAction(UIAlertAction(title:"Confirm", style: .default, handler: { (nil) in
                    self.scannedCode = object.stringValue!
                    self.session.stopRunning()
                }