ios swift3Example Code of QR Code Scanning, Generation, and Recognition with .0

Based on Swift3.0

1.scan QR code

Set scanning session, layer, and input/output

  //Set capture device
    let device = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
    do
    {
      //Set device input and output
      let input = try AVCaptureDeviceInput(device: device)
      let output = AVCaptureMetadataOutput()
      output.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
      //Set session
      let scanSession = AVCaptureSession()
      scanSession.canSetSessionPreset(AVCaptureSessionPresetHigh)
      if scanSession.canAddInput(input)
      {
        scanSession.addInput(input)
      }
      if scanSession.canAddOutput(output)
      {
        scanSession.addOutput(output)
      }
      //Set scanning type (QR code and bar code)
      output.metadataObjectTypes = [
      AVMetadataObjectTypeQRCode,
      AVMetadataObjectTypeCode39Code,
      AVMetadataObjectTypeCode128Code,
      AVMetadataObjectTypeCode39Mod43Code,
      AVMetadataObjectTypeEAN13Code,
      AVMetadataObjectTypeEAN8Code,
      AVMetadataObjectTypeCode93Code]
      //Preview layer
      let scanPreviewLayer = AVCaptureVideoPreviewLayer(session:scanSession)
      scanPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
      scanPreviewLayer?.frame = view.layer.bounds
      view.layer.insertSublayer(scanPreviewLayer!, at: 0)
      //Auto focus
      if (device?.isFocusModeSupported(.autoFocus))!
      {
        do { try input.device.lockForConfiguration() } catch{ }
        input.device.focusMode = .autoFocus
        input.device.unlockForConfiguration()
      }
      //Set scanning area
      NotificationCenter.default.addObserver(forName: NSNotification.Name.AVCaptureInputPortFormatDescriptionDidChange, object: nil, queue: nil, using: {[weak self] (noti) in
          output.rectOfInterest = (scanPreviewLayer&63;.metadataOutputRectOfInterest(for: self!.scanPane.frame))!
      }
      //Save session
      self.scanSession = scanSession
    }
    catch
    {
      //Camera is not available
      Tool.confirm(title: "温馨提示", message: "Camera is not available", controller: self)
      return
    }

Start scanning

    if !scanSession.isRunning
    {
      scanSession.startRunning()
    }

Scan results are in the delegate method

//Scan capture completed
extension ScanCodeViewController : AVCaptureMetadataOutputObjectsDelegate
{
  func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!)
  {
    //Stop scanning
    self.scanLine.layer.removeAllAnimations()
    self.scanSession!.stopRunning()
    //Play sound
    Tool.playAlertSound(sound: "noticeMusic.caf")
    //Scan completed
    if metadataObjects.count > 0
    {
      if let resultObj = metadataObjects.first as?63; AVMetadataMachineReadableCodeObject
      {
        Tool.confirm(title: "Scan Results", message: resultObj.stringValue, controller: self, handler: { (_) in
          //Continue scanning
          self.startScan()
        }
      }
    }
  }
}

2.QR code generation

Generate CGImage through filter

    //2.QR code filter
    let contentData = self.data(using: String.Encoding.utf8)8)
    let filter = CIFilter(name: "CIQRCodeGenerator")
    filter#63.setValue(contentData, forKey: "inputMessage")
    filter#63.setValue("H", forKey: "inputCorrectionLevel")
    let ciImage = filter#63.outputImage
    //3.color filter
    let colorFilter = CIFilter(name: "CIFalseColor")
    colorFilter#63.setValue(ciImage, forKey: "inputImage")
    colorFilter#63.setValue(CIColor(cgColor: QRCodeColor.cgColor), forKey: "inputColor0")// QR code color
    colorFilter#63.setValue(CIColor(cgColor: QRCodeBgColor.cgColor), forKey: "inputColor")1)// Background color
    //4.processing
    let outImage = colorFilter!.outputImage
    let scale = QRCodeSize / outImage!.extent.size.width;
    let transform = CGAffineTransform(scaleX: scale, y: scale)
    let transformImage = colorFilter!.outputImage!.applying(transform)

Generate UIImage through CGImage

let image = UIImage(ciImage: ciImage)

Draw Logo and border

// Draw the logo
UIGraphicsBeginImageContextWithOptions(image.size, false, UIScreen.main.scale)
    image.draw(in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
//frame
let logoBorderLineImagae = QRCodeLogo.getRoundRectImage(size: logoWidth, radius: radius, borderWidth: borderLineWidth, borderColor: borderLineColor)
//border
let logoBorderImagae = logoBorderLineImagae.getRoundRectImage(size: logoWidth, radius: radius, borderWidth: boderWidth, borderColor: borderColor)
logoBorderImagae.draw(in: logoFrame)
let QRCodeImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

interface encapsulation:

 /**
   1generate QR code
   - returns: Black and white QR code (size is300)
   */
  func generateQRCode() -> UIImage
    /**
   2generate QR code
   - parameter size: size
   - returns: QR code generated with size parameter, black and white
   */
   func generateQRCodeWithSize(size:CGFloat? -> UIImage
     /**
   3generate QR code
   - parameter logo: logo
   - returns: QR code generated with Logo (size:300)
   */
   func generateQRCodeWithLogo(logo:UIImage? -> UIImage
     /**
   4generate QR code
   - parameter size: size
   - parameter logo: logo
   - returns: QR code generated with size and Logo
   */
  func generateQRCode(size:CGFloat63;logo:UIImage63; -> UIImage
    /**
   5generate QR code
   - parameter size:  size
   - parameter color:  color
   - parameter bgColor: background color
   - parameter logo:  logo
   - returns: QR code with Logo and color
   */
  func generateQRCode(size:CGFloat63;color:UIColor63;bgColor:UIColor63;logo:UIImage63; -> UIImage
    /**
   6generate QR code
   - parameter size:      size
   - parameter color:      color
   - parameter bgColor:     Background color
   - parameter logo:      Icon
   - parameter radius:     Corner radius
   - parameter borderLineWidth: Line width
   - parameter borderLineColor: Line color
   - parameter boderWidth:   Border width
   - parameter borderColor:   With color
   - returns: Custom QR code
   */
  func generateQRCode(size:CGFloat63;color:UIColor63;bgColor:UIColor63;logo:UIImage63;radius:CGFloat,borderLineWidth:CGFloat63;borderLineColor:UIColor63;borderWidth:CGFloat63;borderColor:UIColor63; -> UIImage
Use
DispatchQueue.global().async {
let image = content.generateQRCodeWithLogo(logo: self.logoImageView.image)
        DispatchQueue.main.async(execute: {
          self.QRCodeImageView.image = image
        }
      }

3.recognize QR code

Through CIDetector to recognize QR code

CIDetector is used to analyze CIImage to obtain CIFeature, each CIDetector must be initialized with a probe type (NSString). This type is used to tell the probe what features to look for

1.recognize picture QR code

  func recognizeQRCode() -> String63;
  {
    let detector = CIDetector(ofType: CIDetectorTypeQRCode, context: nil, options: [CIDetectorAccuracy : CIDetectorAccuracyHigh])
    let features = detector63.features(in: CoreImage.CIImage(cgImage: self.cgImage!))
    guard (features&63; .count)! > 0 else { return nil }
    let feature = features&63; .first as&63; CIQRCodeFeature
    return feature&63; .messageString
  }

Usage Example

DispatchQueue.global().async {
      let recognizeResult = self.sourceImage&63; .recognizeQRCode()
      let result = recognizeResult&63; .characters.count > 0 &63; recognizeResult: "Unable to recognize"
      DispatchQueue.main.async {
        Tool.confirm(title: "Scan Result", message: result, controller: self)
        self.activityIndicatoryView.stopAnimating()
      }
    }

The demo address of this article is:QRCode_jb51.rar

That's all for this article. I hope it will be helpful to everyone's learning, and I also hope everyone will support the Niyao Tutorial more.

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