Error Message: Cannot find 'UIControlEvent' in scope

App Development
1

I a trying to complete a simple Swift project using code only (instead of the Storyboard, but I keep getting an error message that states: “Cannot find ‘UIControlEvent’ in scope”

I’m getting this error message on the same line as my buttonInstance.addTarget code and I can’t figure out why. Could someone please help me figure out what I’m doing wrong here? Thank you. :frowning:

//
//  ViewController.swift
//  UdacityClickCounterProject
//
//  Created by I on 1/8/21.
//

import UIKit

class ViewController: UIViewController {
    
    var count: Int = 0
    var label: UILabel!


    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
      
        
// ************* LABEL *************
        
      
        let labelInstance = UILabel()
     
        labelInstance.frame = CGRect(x: 150, y: 150, width: 60, height: 60)
 
        labelInstance.text = "0"

        view.addSubview(labelInstance)
        
        self.label = labelInstance

        
// ************* BUTTON *************

        
        let buttonInstance = UIButton()
        
        buttonInstance.frame = CGRect(x: 150, y: 250, width: 60, height: 60)
        
        buttonInstance.setTitle("Click Me!", for: .normal)
        
        buttonInstance.setTitleColor(UIColor.systemPink, for: .normal)
        
        view.addSubview(buttonInstance)
        
        

        buttonInstance.addTarget(self, action: #selector(ViewController.incrementCount), for: UIControlEvent.touchUpInside)

    }
    
   @objc func incrementCount() {
        self.count += 1
        self.label.text = "\(self.count)"
    }


}
2

You want UIControl.Event.touchUpInside

Or, since the compiler already knows you need a UIControl.Event there, you can just say .touchUpInside. That’s what’s known as an implicit member expression

1 Like
3

Thank you, Rooster. I’m wondering though, the code that I listed above was taken from my instructor’s code and it worked for her. Did it not work for me because the code is outdated? (The instructor’s code is probably old.)

4

Probably. UIControlEvent was renamed UIControl.Event with back in 2018 when a lot of existing types were converted to nested types.

1 Like
5

Thank you so much, Rooster! I appreciate it. :slight_smile: