Why does a custom UIButton image does not resize in Interface Builder?

Question

Why does a custom UIButton image not resize with the button?

I set its view mode to Scale to Fill in Interface Builder, but unlike a UIImageView image, it d

Answer 1

The best solution I found so far in Swift 2.1 is the following:

self.imageButton.imageView?.clipsToBounds = true
self.imageButton.imageView?.contentMode = UIViewContentMode.ScaleAspectFit

This will scale the image so it has an aspect fit in the imageView.