This a quick reference on how to make UIScrollView work with autolayout
Solution 1: Where the content has a fixed size
class ContentView: UIView {}
class ViewController: UIViewController {
// ...
override func viewDidLoad() {
super.viewDidLoad()
let contentVw = ContentView(frame: CGRect(
x: 0, y: 0,
width: 1024,
height: 1024
))
let scrollVw = UIScrollView()
VFL(view)
.add(subview: scrollVw, name: "scrollVw")
.applyConstraints(formats: [
"H:|[scrollVw]|", "V:|[scrollVw]|"
])
VFL(scrollVw)
.addSubview(contentVw)
scrollVw.backgroundColor = .red
scrollVw.contentSize = contentVw.frame.size
}
}
Solution 2: Where the content has an intrinsicContentSize
class ContentView: UIView {
override var intrinsicContentSize: CGSize {
CGSize(width: 1024, height: 1024)
}
}
class ViewController: UIViewController {
// ...
override func viewDidLoad() {
super.viewDidLoad()
let contentVw = ContentView()
let scrollVw = UIScrollView()
VFL(view)
.add(subview: scrollVw, name: "scrollVw")
.applyConstraints(formats: [
"H:|[scrollVw]|", "V:|[scrollVw]|"
])
VFL(scrollVw)
.add(subview: contentVw, name: "contentVw")
.applyConstraints(formats: [
"H:|[contentVw]|", "V:|[contentVw]|"
])
}
}
Solution 3: Where the content has a flexible size
class ContentView: UIView {
weak var scrollVw: UIScrollView?
override func layoutSubviews() {
super.layoutSubviews()
scrollVw?.contentSize = bounds.size
}
}
class ViewController: UIViewController {
// ...
override func viewDidLoad() {
super.viewDidLoad()
let contentVw = ContentView()
let scrollVw = UIScrollView()
VFL(view)
.add(subview: scrollVw, name: "scrollVw")
.applyConstraints(formats: [
"H:|[scrollVw]|", "V:|[scrollVw]|"
])
VFL(scrollVw)
.add(subview: contentVw, name: "contentVw")
.applyConstraints(formats: [
"H:[contentVw]", "V:[contentVw]"
])
// layout based on grandparent view
VFL(contentVw)
.appendConstraints([
contentVw.leadingAnchor.constraint(equalTo: view.leadingAnchor),
contentVw.trailingAnchor.constraint(
equalTo: view.trailingAnchor,
constant: 1024
),
contentVw.topAnchor.constraint(equalTo: view.topAnchor),
contentVw.bottomAnchor.constraint(
equalTo: view.bottomAnchor,
constant: 1024
),
])
contentVw.scrollVw = scrollVw
}
}
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