How do I adjust the transparency (alpha) of a button in Swift?

Question

My button is flButton but when I try to set the alpha to 0, it gives me the error

Value of type '(Any) -> () has no member alpha".

Do I have to replace Any in the @IBAction line?

import UIKit

class FirstLaunchView: UIViewController {

    @IBOutlet weak var logo1: UIImageView!
    @IBOutlet weak var smiley1: UIImageView!
    @IBOutlet weak var subHapp1: UILabel!
    @IBOutlet weak var happ1: UILabel!
    @IBAction func flButton(_ sender: Any) {

        UserDefaults.standard.set(false, forKey: "name")
        //launchDetector = false

        performSegue(withIdentifier: "toMain", sender: self)
    }

    @IBOutlet weak var firstLaunch: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        logo1.alpha = 0
        smiley1.alpha = 0
        subHapp1.alpha = 0
        happ1.alpha = 0
        flButton.alpha = 0         
    }

Solution 1

Your flButton is an @IBAction function. You should either create an @IBOutlet for your button or do this in your function if you want to keep it:

if let button = sender as? UIButton {
    button.alpha = 0
}

Or you could just change the type of you @IBAction function from:

@IBAction func flButton(_ sender: Any)

To:

@IBAction func flButton(_ sender: UIButton)

And then just set sender.alpha = 0.

Solution 2

Most simple way is what Rashwan L suggested , create an outlet just like logo1,smiley1 like this.

@IBOutlet weak var flButton: UIButton!

after that you can easily change your color by

flButton.alpha = 0