Trying to programmatically add UIScrollView to my App and I keep getting a blank View - ios

Question

Trying to create a UIScrollView and I cant seem to get my labels to appear as I would like them dead center.
lazy var label : UILabel = {
let label = UILabel()
label.text = "center of container view.center of container view"
label.font = UIFont(name: "Bebas Neue", size: 23)!
label.textColor = .black
return label
}()
// Mark: Properties
lazy var contentViewSize = CGSize(width: self.view.frame.width + 1200, height: self.view.frame.height)
// Mark: Views
fileprivate lazy var parentScrollView : UIView = {
var newView = UIView()
newView.translatesAutoresizingMaskIntoConstraints = false
newView.backgroundColor = .black
newView.frame = self.scrollView.bounds
newView.frame.size = contentViewSize
return newView
}()
fileprivate lazy var scrollView : UIScrollView = {
var uiScrollView = UIScrollView(frame: .zero)
uiScrollView.translatesAutoresizingMaskIntoConstraints = false
uiScrollView.frame = view.bounds
uiScrollView.backgroundColor = .gray
uiScrollView.addViewBorder(borderColor: UIColor.gray.cgColor, borderWith: 10, borderCornerRadius: 0)
// uiScrollView.alpha =
uiScrollView.contentSize = contentViewSize
// uiScrollView.autoresizingMask = .flexibleHeight
uiScrollView.showsVerticalScrollIndicator = true
uiScrollView.bounces = true
return uiScrollView
}()
fileprivate lazy var tutorialView : UIStackView = {
var tutView = UIStackView(arrangedSubviews: [label,label,label])
tutView.axis = .horizontal
tutView.backgroundColor = .white
tutView.distribution = .fillEqually
tutView.spacing = 0
return tutView
}()
override func viewDidLoad() {
view.backgroundColor = .white
view.addSubview(scrollView)
scrollView.addSubview(parentScrollView)
parentScrollView.addSubview(tutorialView)
scrollView.widthAnchor.constraint(equalTo:self.view.widthAnchor,multiplier: 0.9).isActive = true
scrollView.heightAnchor.constraint(equalTo:self.view.heightAnchor,multiplier: 0.7).isActive = true
scrollView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
scrollView.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 75).isActive = true
tutorialView.topAnchor.constraint(equalTo: parentScrollView.topAnchor,constant: +10).isActive = true}
It seems that when I add that last constraight with the topAnchor I get a blank screen. When I take that off I actually get the borders between the two views and I am able to do some scrolling.
Any help would be appreciated. Thank you

Answer 1

Did you give a value to the scrollView?
uiScrollView.contentSize.width = 1200
Then give the tutorialView the same width constraint with the other constraints.
NSLayoutConstraint.activate([
tutorialView.widthAnchor.constraint(equalToConstant: 1200),
tutorialView.heightAnchor.constraint(equalTo: uiScrollView.heightAnchor)
])

Answer 2

You have to add tutView.translatesAutoresizingMaskIntoConstraints = false when giving layout constraints in closure of tutorialView and also there are some mistakes in your code. So included some changes in your code and check updated code:
lazy var label : UILabel = {
let label = UILabel()
label.text = "center of container view.center of container view"
label.font = UIFont(name: "Bebas Neue", size: 23)!
label.textColor = .green
return label
}()
// Mark: Properties
lazy var contentViewSize = CGSize(width: self.view.frame.width + 1200, height: self.view.frame.height)
// Mark: Views
fileprivate lazy var parentScrollView : UIView = {
var newView = UIView()
newView.translatesAutoresizingMaskIntoConstraints = false
newView.backgroundColor = UIColor.clear
// newView.layer.borderWidth = 2
// newView.layer.borderColor = UIColor.yellow.cgColor
return newView
}()
fileprivate lazy var scrollView : UIScrollView = {
var uiScrollView = UIScrollView()
uiScrollView.translatesAutoresizingMaskIntoConstraints = false
// uiScrollView.frame = view.bounds
uiScrollView.backgroundColor = .orange
uiScrollView.layer.borderColor = UIColor.blue.cgColor
uiScrollView.layer.borderWidth = 2
uiScrollView.layer.cornerRadius = 0
// uiScrollView.alpha =
uiScrollView.contentSize = contentViewSize
// uiScrollView.autoresizingMask = .flexibleHeight
uiScrollView.showsVerticalScrollIndicator = true
uiScrollView.bounces = true
return uiScrollView
}()
fileprivate lazy var tutorialView : UIStackView = {
var tutView = UIStackView(arrangedSubviews: [label,label,label])
tutView.axis = .horizontal
tutView.backgroundColor = .red
tutView.distribution = .fill
tutView.translatesAutoresizingMaskIntoConstraints = false
return tutView
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
view.addSubview(scrollView)
scrollView.addSubview(parentScrollView)
parentScrollView.addSubview(tutorialView)
scrollView.widthAnchor.constraint(equalTo:self.view.widthAnchor,multiplier: 0.9).isActive = true
scrollView.heightAnchor.constraint(equalTo:self.view.heightAnchor,multiplier: 0.7).isActive = true
scrollView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
scrollView.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor, constant: 25).isActive = true
parentScrollView.centerXAnchor.constraint(equalTo: scrollView.centerXAnchor).isActive = true
parentScrollView.topAnchor.constraint(equalTo: scrollView.topAnchor, constant: 10).isActive = true
parentScrollView.heightAnchor.constraint(equalToConstant: 200).isActive = true
parentScrollView.widthAnchor.constraint(equalToConstant: 200).isActive = true
// scrollView.layer.borderWidth = 2
// scrollView.layer.borderColor = UIColor.blue.cgColor
tutorialView.heightAnchor.constraint(equalTo: parentScrollView.heightAnchor).isActive = true
tutorialView.widthAnchor.constraint(equalToConstant: 1200).isActive = true
}