iOs swift activity indicator

swiftActivityIndicator.swift

var spinner: UIActivityIndicatorView!

func setupSpinner(){
        spinner = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 40, height:40))
        spinner.color = UIColor.gray
        self.spinner.center = CGPoint(x:UIScreen.main.bounds.size.width / 2, y:UIScreen.main.bounds.size.height / 2)
        self.view.addSubview(spinner)
        spinner.hidesWhenStopped = true
    }

spinner.startAnimating()

DispatchQueue.main.async {
                self.spinner.stopAnimating()
            }