UIButton close X Swift

CloseButton.playground

import UIKit
import PlaygroundSupport

func getCloseButton(frame: CGRect, color: UIColor) -> UIButton? {
    guard frame.size.width == frame.size.height else { return nil }
    let button = UIButton(type: .custom)
    button.frame = frame
    button.setTitleColor(color, for: .normal)
    button.setTitle("X", for: .normal)
    button.layer.borderColor = color.cgColor
    button.layer.borderWidth = 1
    button.layer.cornerRadius = frame.size.height / 2.0
    return button
}

let containerView = UIView(frame: CGRect(x: 0, y: 0, width: 80, height: 80))
containerView.backgroundColor = UIColor.blue
let buttonFrame = CGRect(x: 20, y: 20, width: 36, height: 36)
if let button = getCloseButton(frame: buttonFrame, color: .white) {
    containerView.addSubview(button)
}
PlaygroundPage.current.liveView = containerView

Example