Swift - Alert 만들기

//ViewController
 
import UIKit
 
class ViewController: UIViewController {
 
    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.
    }

    @IBAction func buttonTapped(sender: AnyObject) {
        // alertView를 삽입
        var alertView = UIAlertController(title: "Stop! SmartPhone!", message: "D.N.U!", preferredStyle: UIAlertControllerStyle.Alert)
        // alertview에 확인버튼 삽입
        alertView.addAction(UIAlertAction(title: "return", style: UIAlertActionStyle.Default, handler: nil))
        
        // 현재 viewcontroller에 추가하기
        self.presentViewController(alertView, animated: true, completion: nil)
    }
 
}