Unable to Scan QR from gallery image

Question

I am trying to make a QR code scanner, which takes an image from the gallery on button click and show a message.

My Button function is:-

@IBAction func gallaryBtnEventListener(_ sender: Any) {
        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerController.SourceType.photoLibrary) {
            pickerController.delegate = self
            pickerController.sourceType = UIImagePickerController.SourceType.photoLibrary
            pickerController.allowsEditing = true
            self.present(pickerController, animated: true, completion: nil)
        }
        
    }

And this is the imagepickerCOntroller

private func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        if let qrcodeImg = info[UIImagePickerController.InfoKey.originalImage.rawValue] as? UIImage {
              let detector:CIDetector=CIDetector(ofType: CIDetectorTypeQRCode, context: nil, options: [CIDetectorAccuracy:CIDetectorAccuracyHigh])!
              let ciImage:CIImage=CIImage(image:qrcodeImg)!
              var qrCodeLink=""
    
              let features=detector.features(in: ciImage)
              for feature in features as! [CIQRCodeFeature] {
                  qrCodeLink += feature.messageString!
              }
              
              if qrCodeLink=="" {
                  print("nothing")
              }else{
                  print("message: \(qrCodeLink)")
              }
          }
          else{
             print("Something went wrong")
          }
         self.dismiss(animated: true, completion: nil)
        }

When I run this code I successfully can select an image from the gallery, but it's print nothing. Now I need help regarding this. One more thing, I did not add any imageView.

Answer 1

It's because you're adding the private access modifier for the UIImagePickerControllerDelegate method imagePickerController(_:,didFinishPickingMediaWithInfo:). Remove the private keyword in front of the method and the delegate will start to work fine. Also, do not copy/paste the delegate methods you're using the old version, here's the newer version:

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    if let qrcodeImg = info[.originalImage] as? UIImage {
        //...
    }
}