UIRefreshControl – does the scroll view need to be "full" for this to work? – Ios swift

Here is about as basic of an example as you can get…

class ViewController: UIViewController {

    let scrollView = UIScrollView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        scrollView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(scrollView)
        
        let g = view.safeAreaLayoutGuide
        
        NSLayoutConstraint.activate([

            // let's constrain the scroll view with 20-points on all sides
            //  so we can easily distinguish it from the main view
            scrollView.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
            scrollView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
            scrollView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
            scrollView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),

        ])
        
        // give it a background color so we can see it
        scrollView.backgroundColor = .red
        
        // Add the refresh control
        scrollView.refreshControl = UIRefreshControl()
        scrollView.refreshControl?.addTarget(self, action: #selector(handleRefreshControl), for: .valueChanged)

    }

    @objc func handleRefreshControl() {
        // do whatever you do to get new content
        print("refresh the content")
        
        // let's simulate a 1-second task to get new content
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
            self.scrollView.refreshControl?.endRefreshing()
        }
    }

}

Note that we didn’t even add any subviews to the scroll view, and the refresh control still works.