如何使UIImageView居中，然后使其宽度增大或缩小到屏幕宽度的定义百分比？

let imageView = UIImageView(image: UIImage(named: "image_name"))

imageView.contentMode = .center

view.addSubview(imageView)

imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.8).isActive = true
imageView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
imageView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true