Making a UIButton a % of the screen size

Question

I noticed certain button sizes look great on one the iPhone 5 simulator but do not look as good on the iPhone 6 simulator and this is because the heights or constraints that

Answer 1

Swift 4.2

In code it's really easy:

override func viewDidLoad() {
        super.viewDidLoad()

        view.addSubview(button)
        button.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        button.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true

        button.widthAnchor.constraint(equalToConstant: 100).isActive = true
        button.heightAnchor.constraint(equalToConstant: UIScreen.main.bounds.height * 0.4).isActive = true
    }

or use this instead of current heightAnchor:

button.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.4).isActive = true

hope this help :)