Swift alert view with OK and Cancel: which button tapped?

I have an alert view in Xcode written in Swift and I'd like to determine which button the user selected (it is a confirmation dialog) to do nothing or to execute something.

Currently I have:

@IBAction func pushedRefresh(sender: AnyObject) {
    var refreshAlert = UIAlertView()
    refreshAlert.title = "Refresh?"
    refreshAlert.message = "All data will be lost."
    refreshAlert.addButtonWithTitle("Cancel")
    refreshAlert.addButtonWithTitle("OK")
    refreshAlert.show()
}

I'm probably using the buttons wrong, please do correct me since this is all new for me.

If you are using iOS8, you should be using UIAlertController — UIAlertView is deprecated.

Here is an example of how to use it:

var refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertControllerStyle.Alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .Default, handler: { (action: UIAlertAction!) in
  print("Handle Ok logic here")
  }))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: { (action: UIAlertAction!) in
  print("Handle Cancel Logic here")
  }))

presentViewController(refreshAlert, animated: true, completion: nil)

As you can see the block handlers for the UIAlertAction handle the button presses. A great tutorial is here (although this tutorial is not written using swift): http://hayageek.com/uialertcontroller-example-ios/

Swift 3 update:

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertControllerStyle.alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
    print("Handle Ok logic here")
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
    print("Handle Cancel Logic here")
}))

present(refreshAlert, animated: true, completion: nil)

Swift 5 update:

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertControllerStyle.alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
      print("Handle Ok logic here")
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
      print("Handle Cancel Logic here")
}))

present(refreshAlert, animated: true, completion: nil)

Swift 5.3 update:

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertController.Style.alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
      print("Handle Ok logic here")
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
      print("Handle Cancel Logic here")
}))

present(refreshAlert, animated: true, completion: nil)

var refreshAlert = UIAlertController(title: "Log Out", message: "Are You Sure to Log Out ? ", preferredStyle: UIAlertControllerStyle.Alert)

refreshAlert.addAction(UIAlertAction(title: "Confirm", style: .Default, handler: { (action: UIAlertAction!) in
    self.navigationController?.popToRootViewControllerAnimated(true)
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .Default, handler: { (action: UIAlertAction!) in

    refreshAlert .dismissViewControllerAnimated(true, completion: nil)


}))

presentViewController(refreshAlert, animated: true, completion: nil)

You can easily do this by using UIAlertController

let alertController = UIAlertController(
       title: "Your title", message: "Your message", preferredStyle: .alert)
let defaultAction = UIAlertAction(
       title: "Close Alert", style: .default, handler: nil)
//you can add custom actions as well 
alertController.addAction(defaultAction)

present(alertController, animated: true, completion: nil)

.

Reference: iOS Show Alert

> Updated for swift 3:

// function defination:

@IBAction func showAlertDialog(_ sender: UIButton) {
        // Declare Alert
        let dialogMessage = UIAlertController(title: "Confirm", message: "Are you sure you want to Logout?", preferredStyle: .alert)
        
        // Create OK button with action handler
        let ok = UIAlertAction(title: "OK", style: .default, handler: { (action) -> Void in
             print("Ok button click...")
             self.logoutFun()
        })
        
        // Create Cancel button with action handlder
        let cancel = UIAlertAction(title: "Cancel", style: .cancel) { (action) -> Void in
            print("Cancel button click...")
        }
        
        //Add OK and Cancel button to dialog message
        dialogMessage.addAction(ok)
        dialogMessage.addAction(cancel)
        
        // Present dialog message to user
        self.present(dialogMessage, animated: true, completion: nil)
    }

// logoutFun() function definaiton :

func logoutFun()
{
    print("Logout Successfully...!")
}

Very Simple
Step # 1: Make a new Classs

    class AppAlert: NSObject {
    
    //Singleton class
    static let shared = AppAlert()
    
    //MARK: - Delegate
    
    var onTapAction : ((Int)->Void)?
    
    //Simple Alert view
    public func simpleAlert(view: UIViewController, title: String?, message: String?){
        ToastManager.show(title: title ?? "", state: .error)
    }
    
    //Simple Alert view with button one
    public func simpleAlert(view: UIViewController, title: String, message: String, buttonTitle: String) {
        
        let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertController.Style.alert)
        //okButton Action
        let okButton = UIAlertAction(title: buttonTitle, style: UIAlertAction.Style.default) {
            (result : UIAlertAction) -> Void in
            self.onTapAction?(0)
        }
        alert.addAction(okButton)
        view.present(alert, animated: true, completion: nil)
    }
    
    //Simple Alert view with two button
    public func simpleAlert(view: UIViewController, title: String, message: String, buttonOneTitle: String, buttonTwoTitle: String){
        let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertController.Style.alert)
        
        //Button One Action
        let buttonOne = UIAlertAction(title: buttonOneTitle, style: UIAlertAction.Style.default) {
            (result : UIAlertAction) -> Void in
            self.onTapAction?(0)
        }
        
        //Button Two Action
        let buttonTwo = UIAlertAction(title: buttonTwoTitle, style: UIAlertAction.Style.default) {
            (result : UIAlertAction) -> Void in
            self.onTapAction?(1)
        }
        alert.addAction(buttonOne)
        alert.addAction(buttonTwo)
        view.present(alert, animated: true, completion: nil)
    }
    
}

Step # 2: Call As

AppAlert.shared.simpleAlert(view: self, title: "Register First", message: "Please Register to Proceed", buttonOneTitle: "Cancel", buttonTwoTitle: "OK")
        AppAlert.shared.onTapAction = { [weak self] tag in
            guard let self = self else {
                return
            }
            if tag == 0 {
               
            }else if tag == 1 {
                
            }
        }

You may want to consider using SCLAlertView, alternative for UIAlertView or UIAlertController.

UIAlertController only works on iOS 8.x or above, SCLAlertView is a good option to support older version.

github to see the details

example:

let alertView = SCLAlertView()
alertView.addButton("First Button", target:self, selector:Selector("firstButton"))
alertView.addButton("Second Button") {
    print("Second button tapped")
}
alertView.showSuccess("Button View", subTitle: "This alert view has buttons")

small update for swift 5:

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertController.Style.alert)

    refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
          print("Handle Ok logic here")
    }))

    refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
          print("Handle Cancel Logic here")
    }))

    self.present(refreshAlert, animated: true, completion: nil)