ios swift Button, Label, AlertView

 import UIKit class ViewController: UIViewController , UIAlertViewDelegate { @IBOutlet var label: UILabel? @IBOutlet var btn: UIButton? @IBAction func btnClick(AnyObject) { showAlert() } func showAlert() { let alert = UIAlertView() alert.title = "Alert" alert.delegate = self alert.message = "Hello Apple" alert.addButtonWithTitle("OK") alert.addButtonWithTitle("Cancel") alert.show() } override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib.

 } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated.

 } func alertView(alertView: UIAlertView!, clickedButtonAtIndex buttonIndex: Int) { switch buttonIndex { case 0: self.label?.text = "ok"; case 1: self.label?.text = "cancel"

        default: println("alertView cancel!") } } }