UIImageWriteToSavedPhotosAlbum unreliable

Question

WorikStanton OP

Created Dec ’21

Replies 2

Boosts 0

Views 1.8k

Participants 1

UIImageWriteToSavedPhotosAlbum is not working reliably for me.

It seems to work about a third of the times I call it.

When I say does not work, I mean the callback is not called, and it silently returns

When I use the code snipped below I get the results:

 Call UIImageWriteToSavedPhotosAlbum
Called UIImageWriteToSavedPhotosAlbum

If I call it twice in a row sometimes the first call works, never the second.

Neither of the print statements in the callback are executed

 class ImageSaver: NSObject {
    func writeToPhotoAlbum(image: UIImage) {
        print("Call UIImageWriteToSavedPhotosAlbum")
        UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
        print("Called UIImageWriteToSavedPhotosAlbum")
    }
 
    // https://www.hackingwithswift.com/example-code/media/uiimagewritetosavedphotosalbum-how-to-write-to-the-ios-photo-album
    @objc func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {
        if let error = error {
            // we got back an error!
            print("Error: \(error.localizedDescription)")
        } else {
            print ("Image saved")
        }
    }
}

Boost

Answer 1

WorikStanton OP

Dec ’21

Do I need to use a semephore to serialise the callback? If I call UIImageWriteToSavedPhotosAlbum twice without waiting for the callback to complete will the second call fail silently?

0

Answer 2

WorikStanton OP

Dec ’21

This is ongoing.

I simplified the code to:

 import UIKit
func SaveImageAsPhoto(image:UIImage) {
    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
}

and I get the same results. At best it works half the time.

0

	Call UIImageWriteToSavedPhotosAlbum
	Called UIImageWriteToSavedPhotosAlbum

	class ImageSaver: NSObject {
	func writeToPhotoAlbum(image: UIImage) {
	print("Call UIImageWriteToSavedPhotosAlbum")
	UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
	print("Called UIImageWriteToSavedPhotosAlbum")
	}

	// https://www.hackingwithswift.com/example-code/media/uiimagewritetosavedphotosalbum-how-to-write-to-the-ios-photo-album
	@objc func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {
	if let error = error {
	// we got back an error!
	print("Error: \(error.localizedDescription)")
	} else {
	print ("Image saved")
	}
	}
	}

	import UIKit
	func SaveImageAsPhoto(image:UIImage) {
	UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
	}