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

Swift 2+

    class ViewController: UITableViewController {
        weak var activityIndicatorView: UIActivityIndicatorView!

        override func viewDidLoad() {
            super.viewDidLoad()
            let activityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.Gray)
            tableView.backgroundView = activityIndicatorView
            self.activityIndicatorView = activityIndicatorView
            activityIndicatorView.startAnimating()

        }
        ...
    }