Scroll view paging content size doesn't work with iphone 5s ios 12 - swift

Question

I have an horizontal paging scroll view with 3 images.
This is the code in my viewDidLoad:
for index in 0..<images.count {
frame.origin.x = scrollView.frame.size.width * CGFloat(index)
frame.size = scrollView.frame.size
let UrlImage = NSURL(string: images[index] as! String)
let dataImage = NSData(contentsOf: UrlImage! as URL)
if dataImage != nil {
let imgView = UIImageView(frame: frame)
imgView.image = UIImage(data: dataImage! as Data)
imgView.contentMode = .scaleAspectFit
self.scrollView.backgroundColor = .lightGray
self.scrollView.addSubview(imgView)
}
}
scrollView.contentSize = CGSize(width: (scrollView.frame.size.width * CGFloat(images.count)), height: scrollView.frame.size.height)
scrollView.delegate = self
and this is the result:
If i try with last iphone devices it works properly. But if i try with iphone 5s with ios12, content size doesn't work and this is the result:
How can i fix this? I'v been trying for 3 days

Answer 1

I'm assuming you have code to handle the page control and scroll delegate(s)...
Here's a very simple example of using a UIStackView to hold the 3 image views:
class ViewController: UIViewController {
let scrollView = UIScrollView()
let stack = UIStackView()
let pageControl = UIPageControl()
override func viewDidLoad() {
super.viewDidLoad()
// scroll view properties
scrollView.backgroundColor = .gray
scrollView.isPagingEnabled = true
// stack view properties
stack.axis = .horizontal
stack.alignment = .fill
stack.distribution = .fillEqually
stack.spacing = 0
// page control properties
pageControl.backgroundColor = .white
pageControl.pageIndicatorTintColor = .darkGray
pageControl.currentPageIndicatorTintColor = .blue
// we're going to use constraints
scrollView.translatesAutoresizingMaskIntoConstraints = false
stack.translatesAutoresizingMaskIntoConstraints = false
pageControl.translatesAutoresizingMaskIntoConstraints = false
scrollView.addSubview(stack)
view.addSubview(scrollView)
view.addSubview(pageControl)
// respect safe area
let g = view.layoutMarginsGuide
NSLayoutConstraint.activate([
// scroll view constrained Top / Leading / Trailing
scrollView.topAnchor.constraint(equalTo: g.topAnchor),
scrollView.leadingAnchor.constraint(equalTo: g.leadingAnchor),
scrollView.trailingAnchor.constraint(equalTo: g.trailingAnchor),
// scroll view height = 1/2 of view height
scrollView.heightAnchor.constraint(equalTo: g.heightAnchor, multiplier: 0.5),
// stack view constrained Top / Bottom / Leading / Trailing of scroll view
stack.topAnchor.constraint(equalTo: scrollView.topAnchor),
stack.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor),
stack.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor),
stack.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor),
// stack view height == scroll view height
stack.heightAnchor.constraint(equalTo: scrollView.heightAnchor),
// page control centered horizontally just below the scroll view
pageControl.topAnchor.constraint(equalTo: scrollView.bottomAnchor, constant: 4.0),
pageControl.centerXAnchor.constraint(equalTo: scrollView.centerXAnchor),
])
// add three image views to the stack view
for _ in 1...3 {
let v = UIImageView()
v.backgroundColor = .lightGray
v.contentMode = .scaleAspectFit
stack.addArrangedSubview(v)
}
// stack distribution is set to .fillEqually, so we only need to set the
// width constraint on the first image view
// unwrap it
if let v = stack.arrangedSubviews.first {
// stack view has 8-pts on each side
v.widthAnchor.constraint(equalTo: scrollView.widthAnchor).isActive = true
}
pageControl.numberOfPages = 3
// set delegates...
// implement page control funcs...
// etc...
// start image retrieval process
downloadImages()
}
func downloadImages() -> Void {
// get 3 "placeholder" images
// 400x300 400x400 300x400
let urls: [String] = [
"https://via.placeholder.com/400x300.png/FF0000/FFF",
"https://via.placeholder.com/400x400.png/00AA00/FFF",
"https://via.placeholder.com/300x400.png/0000FF/FFF",
]
for (v, urlString) in zip(stack.arrangedSubviews, urls) {
if let imgView = v as? UIImageView, let url = URL(string: urlString) {
imgView.load(url: url)
}
}
}
}
// async download image url from: https://www.hackingwithswift.com/example-code/uikit/how-to-load-a-remote-image-url-into-uiimageview
extension UIImageView {
func load(url: URL) {
DispatchQueue.global().async { [weak self] in
if let data = try? Data(contentsOf: url) {
if let image = UIImage(data: data) {
DispatchQueue.main.async {
self?.image = image
}
}
}
}
}
}