Empty space in UIImageView when using scaleAspectFit - ios

Question

Here is an image of my issue. My problem is that I have an tiny empty space on the right side of my UIImageView that is constrained to the view of my view controller. It's green because of the background I set, and it is more prominent on my device. It's weird because the image should fit the whole screen considering the image was taken on the phone itself and I am using scaleAspectFit.
let imageView: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.isUserInteractionEnabled = true
imageView.contentMode = .scaleAspectFit
imageView.backgroundColor = .green
imageView.clipsToBounds = true
return imageView
}()
Here is the code for the constraints:
func setupImageView() {
self.view.addSubview(imageView)
let imageViewConstraints = [
imageView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
imageView.topAnchor.constraint(equalTo: self.view.topAnchor),
imageView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
imageView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor)
]
NSLayoutConstraint.activate(imageViewConstraints)
}
I am basically setting the image using self.imageView.image and I end up with a empty space on the right side that is only noticeable when using bright colors as the imageView background. Not sure if this is a bug. The only reason I'm not using fill is because I want to maintain the aspect while showing the whole image.

Answer 1

The contentMode scaleAspectFit will keep the scale of the image, display the whole content of the image. Because your photo scale is same to the screen, if your imageView height is less than screen, the image display width will be less than screen too, which causes the background green color shows.
To ensure the imageView fits the screen, you can add border on it:
imageView.layer.borderColor = UIColor.red.cgColor
imageView.layer.borderWidth = 1.0

Answer 2

Try to use in your imageView{
imageView.contentMode = .scaleAspectFill
}