Using ScrollView Programmatically in Swift 3

Question

I have searched other questions and seem to still have some trouble creating my scrollView programmatically with autolayout in swift 3. I am able to get my scrollview to sho

Answer 1

Two things.

1. Add the labels to scroll view, not your view

You want your label to scroll with scroll view, then you should not add it on your view. When running your code, you can scroll but the fixed label there is pinned to your view, not on your scroll view

2. Make sure you added your constraints correctly

Try it on your storyboard about what combination of constraint is enough for a view. At least 4 constraints are needed for a label.

Bottom line

Here is a modified version of your code. For constraint I added padding left, padding top, width and height and it works. My code is

let labelOne: UILabel = {
    let label = UILabel()
    label.text = "Scroll Top"
    label.backgroundColor = .red
    label.translatesAutoresizingMaskIntoConstraints = false
    return label
}()

let labelTwo: UILabel = {
    let label = UILabel()
    label.text = "Scroll Bottom"
    label.backgroundColor = .green
    label.translatesAutoresizingMaskIntoConstraints = false
    return label
}()


override func viewDidLoad() {
    super.viewDidLoad()

    let screensize: CGRect = UIScreen.main.bounds
    let screenWidth = screensize.width
    let screenHeight = screensize.height
    var scrollView: UIScrollView!
    scrollView = UIScrollView(frame: CGRect(x: 0, y: 120, width: screenWidth, height: screenHeight))

    scrollView.addSubview(labelTwo)

    NSLayoutConstraint(item: labelTwo, attribute: .leading, relatedBy: .equal, toItem: scrollView, attribute: .leadingMargin, multiplier: 1, constant: 10).isActive = true
    NSLayoutConstraint(item: labelTwo, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 200).isActive = true
    NSLayoutConstraint(item: labelTwo, attribute: .top, relatedBy: .equal, toItem: scrollView, attribute: .topMargin, multiplier: 1, constant: 10).isActive = true
    NSLayoutConstraint(item: labelTwo, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 30).isActive = true

    scrollView.contentSize = CGSize(width: screenWidth, height: 2000)
    view.addSubview(scrollView)

}

And the scroll view looks like this