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

Attila Marosi
Attila Marosi
6,144 Points
Posted by Attila Marosi
Attila Marosi
6,144 Points

Hello, could anyone help me? I've stucked in this exercise (I'm using Swift 3).

In the Code Challenge, I have to add the following constraints to the sampleView:

  • Height constraint of 50 points
  • Width constraint of 50 points
  • Center horizontally and vertically in center

Please help! Thank you in advance!

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 a = NSLayoutConstraint(item: sampleView, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 50.0)
                let b = NSLayoutConstraint(item: sampleView, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 50.0)
                let c = NSLayoutConstraint(item: sampleView, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1.0, constant: 0.0)
                let d = NSLayoutConstraint(item: sampleView, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1.0, constant: 0.0)

  view.addConstraints([a,b,c,d])




    }
}

1 Answer