‘UIAlertView’ was deprecated in iOS 9.0. Use UIAlertController with a preferredStyle of UIAlertControllerStyleAlert instead

See this Code Destructive and OK buttons in UIAlertController:

let alertController = UIAlertController(title: "Destructive", message: "Simple alertView demo with Destructive and Ok.", preferredStyle: UIAlertControllerStyle.alert) //Replace UIAlertControllerStyle.Alert by UIAlertControllerStyle.alert
let DestructiveAction = UIAlertAction(title: "Destructive", style: UIAlertActionStyle.Destructive) {
    (result : UIAlertAction) -> Void in
    print("Destructive")
}

// Replace UIAlertActionStyle.Default by UIAlertActionStyle.default
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default) {
    (result : UIAlertAction) -> Void in
    print("OK")
}

alertController.addAction(DestructiveAction)
alertController.addAction(okAction)
self.presentViewController(alertController, animated: true, completion: nil)

Swift 3:

let alertController = UIAlertController(title: "Destructive", message: "Simple alertView demo with Destructive and Ok.", preferredStyle: UIAlertControllerStyle.alert) //Replace UIAlertControllerStyle.Alert by UIAlertControllerStyle.alert

let DestructiveAction = UIAlertAction(title: "Destructive", style: UIAlertActionStyle.destructive) {
                        (result : UIAlertAction) -> Void in
    print("Destructive")
}

                    // Replace UIAlertActionStyle.Default by UIAlertActionStyle.default

let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default) {
                        (result : UIAlertAction) -> Void in
    print("OK")
}

alertController.addAction(DestructiveAction)
alertController.addAction(okAction)
self.present(alertController, animated: true, completion: nil)

See Alert With Destructive and OK Button: