无法从图库图像中扫描二维码

Question

我正在尝试制作一个 QR 码扫描仪，它会在单击按钮时从图库中获取图像并显示一条消息。

我的按钮功能是：-

@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)
        }
        
    }

这是 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)
        }

当我运行这段代码时，我成功地 select 了图库中的一张图片，但它什么也没打印。现在我需要这方面的帮助。还有一点，我没有添加任何imageView。

Answer 1

这是因为您要为 UIImagePickerControllerDelegate 方法 imagePickerController(_:,didFinishPickingMediaWithInfo:) 添加 private 访问修饰符。删除方法前面的 private 关键字，委托将开始正常工作。另外，不要 copy/paste 使用旧版本的委托方法，这里是新版本：

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

无法从图库图像中扫描二维码

Unable to Scan QR from gallery image

uiimagepickercontroller

swift