How to make a UIView fill the screen using Auto Layout anchors

Swift version: 5.2

Paul Hudson @twostraws May 28th 2019

You can make one view fill all available space inside another by pinning all four of its anchors to the same anchors in its parent container. If you use this when the parent container is the view for your view controller, your child view will fill the screen.

Although it takes only four lines of code, this is the sort of thing I’d put into an extension:

extension UIView {
    func pinEdges(to other: UIView) {
        leadingAnchor.constraint(equalTo: other.leadingAnchor).isActive = true
        trailingAnchor.constraint(equalTo: other.trailingAnchor).isActive = true
        topAnchor.constraint(equalTo: other.topAnchor).isActive = true
        bottomAnchor.constraint(equalTo: other.bottomAnchor).isActive = true
    }
}

You can now call pinEdges(to: someOtherView) directly on the view you want to adjust.