UIImage 必须符合PHPickerViewControllerDelegate回调中的_ObjectiveCBridgeable

Question

I have reviewed the WWDC2020 video explaining how to adopt the new PHPickerViewController API. I have also seen several blogs showing exactly the following code.

func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
    if let result = results.first, result.itemProvider.canLoadObject(ofClass: UIImage.self) {
        result.itemProvider.loadObject(ofClass: UIImage.self) { (image, error) in
            DispatchQueue.main.async {
                self.parent.didCapture(image)
            }
        }
    } else {
        parent.didCapture(nil)
    }
}

However, this fails for me and the error is quite bizarre.

UIImage must confirm to _ObjectiveCBridgable

I will include a screenshot because it is quite unbelievable

Hardware: M1 chipset

IDE: Xcode 12.4

Answer 1

Type cast image as UIImage before using, that should solve the issue.

if let typeCastedImage = image as? UIImage {
  self.parent.didCapture(typeCastedImage)
}

Answer 2

It depends on how you work with the values inside the function body. There are two implementations for the loadObject() function. One of them can actually accept UIImage.self. In my case, the following code works:

func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
    if let itemProvider = results.first?.itemProvider, itemProvider.canLoadObject(ofClass: UIImage.self) {
        itemProvider.loadObject(ofClass: UIImage.self) { image, error in
            if let image = image as? UIImage {
                DispatchQueue.main.async {
                    self.imageViewField.image = image
                }
            }
        }
    }
}

It is necessary to make a check for conformance to the type of UIImage.