PHPickerViewController 的取消按钮在 iOS 15 中不起作用

Question

I am using PHPickerViewController to pick Image for User Profile Picture Purpose in iOS 15. I am using UIKit framework. I have the following code:

var pickerConfig = PHPickerConfiguration(photoLibrary: .shared())
pickerConfig.selectionLimit = 1
pickerConfig.filter = .images
let pickerView = PHPickerViewController(configuration: pickerConfig)
pickerView.delegate = self
self.present(pickerView, animated: true)

The Picker is working properly for selecting images and delegating the results. But, when the Cancel button is pressed, nothing happens and the Picker is not dismissed as expected.

How to dismiss the PHPickerViewController instance when its own Cancel button is pressed ?

Edit:

The implementation of PHPickerViewControllerDelegate Method is as follows:

func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult])
    {
        results.first?.itemProvider.loadObject(ofClass: UIImage.self) { [unowned self] reading , error in
            guard let image = reading as? UIImage, error == nil else
            {
                DispatchQueue.main.async {
                    picker.dismiss(animated: true)
                    self.profilePictureHasError = true
                    self.toggleDoneButtonEnabled()
                }
                return
            }
            self.profilePictureHasError = false
            DispatchQueue.main.async {
                picker.dismiss(animated: true)
                self.profilePictureHasChanged = self.userProfilePicture != image
                if self.profilePictureHasChanged
                {
                    self.profilePictureView.image = image
                    self.toggleDoneButtonEnabled()
                }
            }
        }
    }

Answer 1

You need to dismiss the picker yourself in the picker(_:didFinishPicking:) delegate method which is called when the user completes a selection or when they tap the cancel button.

From the Apple docs for picker(_:didFinishPicking:) :

The system doesn’t automatically dismiss the picker after calling this method.

For example:

func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
    // Do something with the results here
    picker.dismiss(animated: true)
}

Your current delegate code only calls picker.dismiss when the results array is non-empty (ie when the user has selected images). When the cancel button is tapped, the delegate method is called with an empty results array.

Fix the issue by adding the following to the top of the code in your delegate method:

if results.isEmpty {
    picker.dismiss(animated: true)
    return
}

Answer 2

you just wrap it out in an objc func for making cancel button works

    @objc
    func didOpenPhotos() {
        lazy var pickerConfig = PHPickerConfiguration()
        pickerConfig.filter = .images
        pickerConfig.selectionLimit = 1
        let pickerView = PHPickerViewController(configuration: pickerConfig)
        pickerView.delegate = self
        self.present(pickerView, animated: true)
    }

call it anywhere