How to show activity indicator while tableView loads?

Question

When I switch between my tabs it loads some seconds and I want to know that my data is loading. For that I decided to add an activity indicator.

I wrote a little functio

Answer 1

In order to place the UIActivityIndicator in foreground, even over the eventual UITableViewController separators, I have adopted this solution.

• I have add the UIActivityIndicator programmatically, and add it as a subview of my UINavigationController

  var activityIndicator: UIActivityIndicatorView!
  
  override func viewDidLoad() {
     super.viewDidLoad()
     // Code
     // .... omissis
  
     // Set activity indicator
     activityIndicator = UIActivityIndicatorView(style: .whiteLarge)
     activityIndicator.color = UIColor.darkGray
     activityIndicator.center = tableView.center
     activityIndicator.hidesWhenStopped = true
     activityIndicator.stopAnimating()
     self.navigationController?.view.addSubview(activityIndicator)
  }
  

• I have just start & stop it when needed (in my case):

  func animateActivityIndicator(_ sender: Any ) {
     guard let vc = sender as? UIViewController else { return }
     if let v = vc as? MyTableViewController {
         if v.activityIndicator.isAnimating {
             v.activityIndicator.stopAnimating()
         } else {
             v.activityIndicator.startAnimating()
         }
     }
     // Others UIViewController or UITableViewController follows...
     // all of them exhibits an activityIndicator variable
     // implemented programmatically or with the storyboard
  }
  

PS. My environment is Xcode 10.0, iOS 12.0