CODEWITHSUNDEEP
iosswift3selector
Kamil Harasimowicz
Kamil Harasimowicz

Reputation: 4984

Selector method does not call

I have simply UIViewController class: 

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        var _ = Test(parentView: view)
    }
}

and another class:

import UIKit

class Test: NSObject {

    let parentView: UIView

    init(parentView: UIView) {
        self.parentView = parentView

        super.init()

        addButton()
    }
}

extension Test {

    func addButton() {
        let button = UIButton(type: .custom)
        button.frame.size = CGSize(width: 100, height: 100)
        button.addTarget(self, action: #selector(tap(_:)), for: .touchUpInside)
        button.backgroundColor = UIColor.red
        parentView.addSubview(button)
    }

    func tap(_ sender: UIButton) {
        print("Tap")
    }
}

Test class inherits NSObject because without it I get compilator massage Argument of '#selector' refers to instance method 'tap(sender:)' that is not exposed to Objective-C.

The problem is that method tap(sender: UIButton) does not call. I don't know why.

(Swift 3, Xcode 8.2.1, appTarget: iOS 9.0)

Edit 1

I edited implementation of Test class according @vadian suggestions but it still does not work.

Edit 2

When I move Test class implementation to ViewController everything works but I don't want to do this. Why this not work in separate class?

Upvotes: 3

Views: 326

Answers (1)

Nirav D
Nirav D

Reputation: 72410

I have test your project the problem is in this line var _ = Test(parentView: view), where you are creating object of your custom class Test. So after th viewDidLoad its instance is loss or deinit. Thats the reason you are not getting action call with button.

To solve the issue declare one instance property of type Test inside your ViewController class and initialize this property in viewDidLoad. Now it will call action when you tap on button.

class ViewController: UIViewController {

    var test: Test?       

    override func viewDidLoad() {
        super.viewDidLoad()

        self.test = Test(parentView: view)
    }
}

Upvotes: 3

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