UIRefreshControl in UIScrollView Doesn't disappear on endRefreshing

Question

I tried to use a UIRefreshControll in a UIScrollView but I had the problem that I needed to scroll a lot in order to get it to refresh. I needed to use both hands to make it work so I decided to write some scrolling logic to start the refreshing.

Now the problem is that sometimes the endRefreshing function doesn't make the UIRefreshControll view disappear and I end up having it there forever.

I have tried called endRefreshing in the main queue with a delay and it doesn't work. I have also tried setting isHidden to true and also removeFromSuperView. I've had no luck in making it work.

import UIKit

class RefreshableView : UIView {

    @IBOutlet weak var scrollView: UIScrollView!

    private let refreshControl = UIRefreshControl()
    private var canRefresh = true
    var refreshFunction: (() -> ())?

    func setupUI() {
        backgroundColor = ColorName.grayColor.color
        scrollView.refreshControl = refreshControl
    }

    func endRefreshing() {
        self.refreshControl.endRefreshing()
    }
}

extension RefreshableView: UIScrollViewDelegate {

    func scrollViewDidScroll(_ scrollView: UIScrollView) {

        if scrollView.contentOffset.y < -100 {
            if canRefresh && !self.refreshControl.isRefreshing {

                self.canRefresh = false
                self.refreshControl.beginRefreshing()

                self.refreshFunction?()
            }
        } else if scrollView.contentOffset.y >= 0 {
            self.canRefresh = true
        }
    }
}

Answer 1

The scroll view's refreshControl handles the pull-to-refresh feature automatically, so you don't need any of the scrollViewDidScroll() code.

Assuming your storyboard looks something like this, where:

• the view with the Red background is an instance of RefreshableView class
• it contains a scroll view (connected via @IBOutlet)
• and some content in the scroll view (here I have just a single label)

Your code can be like this:

class RefreshableView : UIView {

    @IBOutlet var scrollView: UIScrollView!

    private let refreshControl = UIRefreshControl()

    var refreshFunction: (() -> ())?

    func setupUI() {
        backgroundColor = .gray

        refreshControl.addTarget(self, action: #selector(didPullToRefresh), for: .valueChanged)

        scrollView.refreshControl = refreshControl
    }

    @objc func didPullToRefresh() {
        print("calling refreshFunction in controller")
        self.refreshFunction?()
    }

    func endRefreshing() {
        print("end refreshing called from controller")
        self.refreshControl.endRefreshing()
    }

}

class RefreshTestViewController: UIViewController {

    @IBOutlet var theRefreshableView: RefreshableView!

    override func viewDidLoad() {
        super.viewDidLoad()

        theRefreshableView.setupUI()

        theRefreshableView.refreshFunction = {
            print("simulating refresh for 2 seconds...")
            DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
                [weak self] in
                guard let self = self else { return }
                // do what you want to update the contents of theRefreshableView
                // ...
                // then tell theRefreshableView to endRefreshing
                self.theRefreshableView.endRefreshing()
            }
        }
    }

}