Scroll view not scrolling horizontal - swift

Question

I have a custom view, i set it in parent like:
func setup(){
view.backgroundColor = .gray
view.addSubview(chartView)
chartView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
chartView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
chartView.topAnchor.constraint(equalTo: view.topAnchor, constant: statusAndNavigationBarHeight).isActive = true
chartView.heightAnchor.constraint(equalToConstant: Dimensions.chartHeight.value).isActive = true
}
Then in that view i tried to set up a scroll:
scroll = UIScrollView.init(frame: CGRect(x: 0.0, y: 0.0, width: scrollWidth(), // print 728.0
height: Double(Dimensions.chartHeight.value))) // print 400.0
scroll.isScrollEnabled = true
scroll.showsHorizontalScrollIndicator = true
addSubview(scroll)
}
And thats all, when i launch app i can't drag and scroll horizontally, in debug editor i can't see that it is scroll view here lying with large width.

Answer 1

The scrollView doesn't scroll with it's size , it needs a content that define it's content size for example
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let chartView = UIView()
chartView.translatesAutoresizingMaskIntoConstraints = false
chartView.backgroundColor = .red
view.backgroundColor = .gray
view.addSubview(chartView)
chartView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
chartView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
chartView.topAnchor.constraint(equalTo: view.topAnchor, constant: 100).isActive = true
chartView.heightAnchor.constraint(equalToConstant:200).isActive = true
let scroll = UIScrollView(frame: CGRect(x: 0.0,
y: 0.0,
width: UIScreen.main.bounds.size.width, // print 728.0
height: 200.0))
scroll.isScrollEnabled = true
scroll.showsHorizontalScrollIndicator = true
chartView.addSubview(scroll)
let www = UIView()
www.backgroundColor = .green
www.translatesAutoresizingMaskIntoConstraints = false
scroll.addSubview(www)
www.leftAnchor.constraint(equalTo: scroll.leftAnchor).isActive = true
www.rightAnchor.constraint(equalTo: scroll.rightAnchor).isActive = true
www.topAnchor.constraint(equalTo: scroll.topAnchor).isActive = true
www.bottomAnchor.constraint(equalTo: scroll.bottomAnchor).isActive = true
www.heightAnchor.constraint(equalToConstant:200).isActive = true
www.widthAnchor.constraint(equalTo: view.widthAnchor,multiplier:2.0).isActive = true
scroll.addSubview(www)
}
}