Getting access to a UISegementedControl in Swift

Kokanee picture Kokanee · Jul 24, 2014 · Viewed 17.2k times · Source

I have been playing with the UISegmentedControl and want to manage it as needed. I've created it on the storyboard, hooked up the outlet and the action. It visualizes fine and the callback on the action indexchanged works. I want to do some other management of this prior to visualization so I am stuck on how to properly access the mysegmentedControl I setup in the storyboard. Seems like a silly question but I could not find a Swift example for the UISegmentedControl that I could relate to currently.

class ViewController: UIViewController, MKMapViewDelegate {
    ...
    //playing around with a Segmented Control
    @IBOutlet var mysegmentedControl : UISegmentedControl

    // Any time the button is clicked in the Segmented Control the index changes so we catch it to do something.

    @IBAction func indexChanged(sender : UISegmentedControl) {
        // This all works fine and it prints out the value of 3 on any click 
        println("# of Segments = \(sender.numberOfSegments)")

        switch sender.selectedSegmentIndex {
        case 0:
            println("first segement clicked")
        case 1:
            println("second segment clicked")
        case 2:
            println("third segemnet clicked")
        default:
            break;
        }  //Switch
    } // indexChanged for the Segmented Control

    override func viewDidLoad() {
        super.viewDidLoad()

         //  1.  How do I get proper access to the mysegmentedControl that was created in the storyboard and is already displayed.
         //      The indexChanged function gets called fine on the display via sender getting passed to it.
         //      I equate this to getting the pointer to it in C so I leverage it elsewhere
         //  2.  Guessing I don't need to init a new UISegmentedControl or do I?

         // This compiles but crashes on run with: fatal error: Can't unwrap 
         println("# of Segments = \(mysegmentedControl.numberOfSegments)")

    } // viewDidLoad    

} // ViewController

Answer

Avi picture Avi · Jul 24, 2014

Here is what i've used and is working fine for me -

@IBOutlet var mysegmentedControl : UISegmentedControl?

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

@IBAction func indexChanged(sender : UISegmentedControl) {
    // This all works fine and it prints out the value of 3 on any click
    println("# of Segments = \(sender.numberOfSegments)")

    switch sender.selectedSegmentIndex {
    case 0:
        println("first segement clicked")
    case 1:
        println("second segment clicked")
    case 2:
        println("third segemnet clicked")
    default:
        break;
    }  //Switch
} // indexChanged for the Segmented Control

override func viewDidLoad() {
    super.viewDidLoad()
    println("# of Segments = \(mysegmentedControl?.numberOfSegments)")

}