How do I change the color of my custom UIButton's that is registered with IBAction?

Question

I have created a custom UIButton called RegistrationButton. I am currently trying to allow a user to select between three buttons. On select of a button the background color and text will change. Here is how the IBAction looks:

  @IBAction func didTapBUtton(_ sender: UIButton) {


  switch sender {
    case studentButton:
        studentButton.selected()
        professionalButton.notSelected()
        entrepreneurhsip.notSelected()
        break
    case professionalButton:
        studentButton.notSelected()
        professionalButton.selected()
        entrepreneurhsip.notSelected()
        break
    case entrepreneurhsipButton:
        studentButton.notSelected()
        professionalButton.notSelected()
        entrepreneurhsip.selected()
        break
    default:
        break
    }
}

Here is how my custom UIButton class:

import UIKit

class RegistrationButton: UIButton {


override func awakeFromNib() {
    super.awakeFromNib()
    addBorder()

}

required init(coder:NSCoder) {
    super.init(coder:coder)!
}

func addBorder(){
    self.layer.borderColor = UIColor.white.cgColor
    self.layer.borderWidth = 1
}

func selected(){
     self.backgroundColor = .white

    self.setTitleColor(UIColor(red:67,green:204,blue:144,alpha:1), for: .normal)
}
func notSelected(){

    self.backgroundColor = UIColor(red:67,green:204,blue:144,alpha:1)


    self.setTitleColor(UIColor.white, for: .normal)
}

}

However, when I select on one button the background of all is changed to white.

Answer 1

The rgb values have to be floating points between 0 and 1. You just need to divide all of your parameters by 255 to make it work.

So for example

self.backgroundColor = UIColor(red:67,green:204,blue:144,alpha:1)

should be

self.backgroundColor = UIColor(red: 67.0/255, green: 204.0/255, blue:144.0/255, alpha:1)

(the same obviously applies when you apply the title color)

Sidenote: A switch in Swift does not fallthrough by default, so you can omit the breaks. If you explicitly need this behaviour, then there is a fallthrough keyword for that.

Answer 2

If all you want to do is changing the highlight of the buttons then another approach is to connect all the buttons to an outlet collection @IBOutlet var buttons: [UIButton]! in your view/controller. Then, in didTapButton(_ sender: UIButton) you update the buttons' selected property based on which button is tapped (something like this):

@IBAction func didTapBUtton(_ sender: UIButton) {
    // Select the button that was tapped, unselect the other buttons
    buttons.forEach { $0.isSelected = ($0 == sender) }
}

This keeps the code simple on a small scale but becomes inefficient with many buttons as it's a bit wasteful to loop over every single button just to unhighlight one of them. If managing many buttons, another approach would be to use an optional selectedButton property in your controller:

var selectedButton: UIButton?

@IBAction func didTapBUtton(_ sender: UIButton) {
    selectedButton?.isSelected = false
    sender.isSelected = true
    selectedButton = sender
}

or you can utilize the didSet mechanism in Swift:

var selectedButton: UIButton? {
    didSet {
        oldValue?.isSelected = false
        selectedButton.isSelected = true
    }
}

/.../

@IBAction func didTapBUtton(_ sender: UIButton) {
    selectedButton = sender
}

Answer 3

You might get what you see using UIControlEvents.

self.addTarget(target, action: action, for: .touchUpInside)

That's a quick example. Of course, you won't need to things like awakeFromNib and all that other code - let the OS work things.

Here's the other things you can code against **addTarget(for:):

public static var touchDown: UIControlEvents { get } // on all touch downs
public static var touchDownRepeat: UIControlEvents { get } // on multiple touchdowns (tap count > 1)
public static var touchDragInside: UIControlEvents { get }
public static var touchDragOutside: UIControlEvents { get }
public static var touchDragEnter: UIControlEvents { get }
public static var touchDragExit: UIControlEvents { get }
public static var touchUpInside: UIControlEvents { get }
public static var touchUpOutside: UIControlEvents { get }
public static var touchCancel: UIControlEvents { get }

My bottom line? Let the OS do the work for you!