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iOS Introduction to Auto Layout in iOS Auto Layout in Code Using Layout Anchors

Anandita Chakraborty
Anandita Chakraborty
558 Points

Compiler error says UIView has no member layoutMarginsGuide

While trying to write view.layoutMarginsGuide, it shows compiler error

layout.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.activate([
            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)
        ])
        let margins = view.layoutMarginsGuide
        // Add constraint code below
        NSLayoutConstraint.activate([
            greenView.bottomAnchor.constraint(equalTo: margins.bottomAnchor, constant: 8.0),
            greenView.leadingAnchor.constraint(equalTo: margins.leadingAnchor, constant: 8.0),
            greenView.trailingAnchor.constraint(equalTo:margins.trailingAnchor, constant: 8.0),
            greenView.heightAnchor.constraint(equalToConstant: 75.0)
        ])



    }
}