I needed to change image in my UIImageView, but simply setting new image using myImageView.setImage didn’t work. There’s simple workaround

@button = UIView.alloc.initWithFrame(frame)
buttonImage = UIImageView.alloc.initWithFrame(@button.bounds)
buttonImage.setTag(1) # set any number you want
buttonImage.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight
@button.addSubview buttonImage

and now set the image

self.button.viewWithTag(1).setImage(UIImage.imageNamed('answer_bar_white.png').resizableImageWithCapInsets(UIEdgeInsetsMake(18, 18, 18, 18)))

you can remove resizableImageWithCapInsets – I’m using square images to make UIImageView of any size.