UIImageView image does not update visibly when image property is set

Question

I have a UIImageView whose user interaction is true and to which I have given a tap gesture recognizer, whose action handler is as follows:

@IBAction func ta         


        

Answer 1

This seems to be a workaround:

iv.image = im2
delay(0.05) {
    iv.image = nil
    iv.image = im2
}

But what a horror... Omitting any of those assignments, or reducing the delay to zero (e.g. by calling DispatchQueue.main.async instead), causes the workaround to fail.