title: How to add Pull to refresh controller to scrollview?
body: <p>Hi in my application I want to add Pull to refresh controller to scrollview.
  I write the following code but it don't getting any response.</p>
  
  <p>When ever I scroll the view on that time add target method is not called.</p>
  
  <pre><code>@IBOutlet var scrool: UIScrollView!
  var refreshControl = UIRefreshControl()
  
  override func viewDidLoad() {
          super.viewDidLoad()
          // Add refresh control for the Home page scroll view.
          self.refreshControl.tintColor = UIColor.appcolor
          self.refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
          self.refreshControl.addTarget(self, action: #selector(refresh(sender:)), for: UIControl.Event.valueChanged)
          self.scrool.isScrollEnabled = true
          self.scrool.alwaysBounceVertical = true
          scrool.addSubview(refreshControl)
      }
      @objc func refresh(sender:AnyObject) {
          // Code to refresh table view
          self.getHomePageApi()
          refreshControl.endRefreshing()
  
      }
  </code></pre>