スキャン成功後のAVFoundationの停止

Question

iOS 10のSwift 3（Xcode 8.1）を使用したQRコードスキャナーアプリケーションを構築していますが、AVFoundation Frameworkを使用しています。スキャンを成功させた後にスキャンを停止し、画面をタップした後などにスキャナを再起動する方法を知っている人はいますか？

EDIT：

import UIKit 
import AVFoundation 

@available(iOS 10.0, *) 
class QRCodeViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate { 
var captureSession:AVCaptureSession? 
var videoPreviewLayer:AVCaptureVideoPreviewLayer? 
var qrCodeFrameView:UIView? 

let supportedBarCodes = [AVMetadataObjectTypeQRCode, AVMetadataObjectTypeCode128Code, AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeCode93Code, AVMetadataObjectTypeUPCECode, AVMetadataObjectTypePDF417Code, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeAztecCode] 

override func viewDidLoad() { 
    super.viewDidLoad() 

let captureDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo) 

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

     captureSession = AVCaptureSession() 
     captureSession?.addInput(input) 

     let captureMetadataOutput = AVCaptureMetadataOutput() 
     captureSession?.addOutput(captureMetadataOutput) 

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

     captureMetadataOutput.metadataObjectTypes = supportedBarCodes 

     videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession) 
     videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill 
     videoPreviewLayer?.frame = view.layer.bounds 
     view.layer.addSublayer(videoPreviewLayer!) 

     captureSession?.startRunning() 


     qrCodeFrameView = UIView() 

     if case (qrCodeFrameView?.isHidden)! = true  { 
      qrCodeFrameView?.layer.borderColor = UIColor.green.cgColor 
      qrCodeFrameView?.layer.borderWidth = 2 
      view.addSubview(qrCodeFrameView!) 
      view.bringSubview(toFront: qrCodeFrameView!) 
     } 

    } catch { 
     print(error) 
     return 
    } 

} 

override var supportedInterfaceOrientations : UIInterfaceOrientationMask { 
    return UIInterfaceOrientationMask.portrait 
} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 

} 

func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!) { 

    if metadataObjects == nil || metadataObjects.count == 0 { 
     qrCodeFrameView?.frame = CGRect.zero 
     return 
    } 




    let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject 


    if supportedBarCodes.contains(metadataObj.type) { 

     let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj) 
     qrCodeFrameView?.frame = barCodeObject!.bounds 
    print(metadataObj.stringValue) 

} 

Answer 1

あなたのデリゲートメソッド

func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!) { 

if metadataObjects == nil || metadataObjects.count == 0 { 
    qrCodeFrameView?.frame = CGRect.zero 
    return 
} 

let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject 


if supportedBarCodes.contains(metadataObj.type) { 

    let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj) 
    qrCodeFrameView?.frame = barCodeObject!.bounds 
    print(metadataObj.stringValue) 

    // Stop capture session 
    videoPreviewLayer?.isHidden = true 
    qrCodeFrameView?.isHidden = true 
    self.captureSession?.stopRunning() 
}