swift func for constraint
//https://stackoverflow.com/a/26181982/13171606
//open link for further info
override func viewDidLoad() {
let newView = UIView()
newView.backgroundColor = UIColor.red
view.addSubview(newView)
newView.translatesAutoresizingMaskIntoConstraints = false
newView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
newView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
newView.widthAnchor.constraint(equalToConstant: 100).isActive = true
newView.heightAnchor.constraint(equalToConstant: 100).isActive = true
}
override func viewDidLoad() {
let newView = UIView()
newView.backgroundColor = UIColor.red
view.addSubview(newView)
newView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerY, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerY, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100).isActive = true
NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.height, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100).isActive = true
}