Bai Tap Auto Layout 2

BaiTapAutoLayout-2.swift

class MyViewController: UIViewController {
    
    let blueView = UIView()
    let greenView = UIView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(greenView)
        view.addSubview(blueView)
    }
    
    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        blueView.translatesAutoresizingMaskIntoConstraints = false
        greenView.translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activateConstraints([
            NSLayoutConstraint(item: blueView, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 100.0),
            NSLayoutConstraint(item: blueView, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 150.0),
            NSLayoutConstraint(item: blueView, attribute: .Left, relatedBy: .Equal, toItem: view, attribute: .LeftMargin, multiplier: 1.0, constant: 8.0),
            NSLayoutConstraint(item: blueView, attribute: .Top, relatedBy: .Equal, toItem: self.topLayoutGuide, attribute: .Bottom, multiplier: 1.0, constant: 8.0),
            NSLayoutConstraint(item: blueView, attribute: .Right, relatedBy: .Equal, toItem: view, attribute: .RightMargin, multiplier: 1.0, constant: -8.0)
        ])
        
        // Add constraint code below
        
        NSLayoutConstraint.activateConstraints([
            NSLayoutConstraint(item: greenView, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 75.0),
            NSLayoutConstraint(item: greenView, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 150.0),
            NSLayoutConstraint(item: greenView, attribute: .Left, relatedBy: .Equal, toItem: view, attribute: .LeftMargin, multiplier: 1.0, constant: 8.0),
            NSLayoutConstraint(item: greenView, attribute: .Top, relatedBy: .Equal, toItem: blueView, attribute: .Bottom, multiplier: 1.0, constant: 8.0),
            NSLayoutConstraint(item: greenView, attribute: .Right, relatedBy: .Equal, toItem: view, attribute: .RightMargin, multiplier: 1.0, constant: -8.0)
        ])
    }
}