Assign Default Action to all UISlider programmatically

Question

My app is in prototype stage of development. Some sliders do not have any action assigned to them either through storyboard or programmatically.

I need to display an alert when slider drag stops during testing. Can this be done through an extension of UISlider?

How can I assign a default action to UISlider when the drag ends to show an alert unless another action is assigned via interface builder or programmatically?

Similar Question

did it work for you? – Md. Ibrahim Hassan Nov 04 '17 at 08:50 — Md. Ibrahim Hassan, Nov 04 '17 at 08:50
Yes it worked just fine. Thanks :) – nkirit Nov 04 '17 at 08:50 — nkirit, Nov 04 '17 at 08:50

score 4 · Accepted Answer · answered Nov 04 '17 at 08:37

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    self.checkButtonAction()
}

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

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

}

}

extension UIViewController{
    func checkButtonAction(){
        for view in self.view.subviews as [UIView] {
            if let btn = view as? UISlider {
                if (btn.allTargets.isEmpty){
                    btn.add(for: .allTouchEvents, {
                        if (!btn.isTracking){
                            let alert = UIAlertController(title: "Test 3", message:"No selector", preferredStyle: UIAlertControllerStyle.alert)

                            // add an action (button)
                            alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))

                            // show the alert
                            self.present(alert, animated: true, completion: nil)
                        }
                    })
                }
            }
        }

    }
}

class ClosureSleeve {
    let closure: ()->()

init (_ closure: @escaping ()->()) {
    self.closure = closure
}

@objc func invoke () {
    closure()
}
}

extension UIControl {
    func add (for controlEvents: UIControlEvents, _ closure: @escaping ()->()) {
        let sleeve = ClosureSleeve(closure)
        addTarget(sleeve, action: #selector(ClosureSleeve.invoke), for: controlEvents)
        objc_setAssociatedObject(self, String(format: "[%d]", arc4random()), sleeve, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
    }
}

Please check this modified Answer.

Assign Default Action to all UISlider programmatically

1 Answers1