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iOS Introduction to Auto Layout in iOS Auto Layout in Code Constraints in Code

added it to the parent view, doesn't seem to work?

parent view?

layout.swift
class MyViewController: UIViewController {

    let sampleView = UIView()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(sampleView)
    }

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()

       sampleView.translatesAutoresizingMaskIntoConstraints = false

        // Add constraints below

        let sampleViewHeightConstraint = NSLayoutConstraint(item: sampleView, attribute: .Height, relatedBy: .Equal, 
        toItem: nil, attribute: .CenterX, multiplier: 1.0, constant: 50.0)

        let sampleViewWidthConstraint = NSLayoutConstraint(item: sampleView, attribute: .Width, relatedBy: .Equal, 
        toItem: nil, attribute: .CenterX, multiplier: 1.0, constant: 50.0)

        view.addConstraints([sampleViewHeightConstraint,sampleViewWidthConstraint])
    }
}

2 Answers

Moritz Lang
Moritz Lang
25,909 Points

Hi, I'm not quite sure about this old synthax for auto layout, but I think you have to set toItem to your parent view (view). How should it know otherwise that you want to relate it to your superview?

yep Moritz, I had to do it with anchor which was in the next course! As our friend Paramathne says :pretty cool hah?