Underline button text in Swift

Question

I have UIButton. In interface builder I set its title to be \'Attributed\'. How can I make its title to be underlined from code in Swift?

@IBOutlet weak var myBt         


        

Answer 1

if you are looking for a way to do this without inheritance -

swift 3/4/5

// in swift 4 - switch NSUnderlineStyleAttributeName with NSAttributedStringKey.underlineStyle

extension UIButton {
    func underline() {
        guard let text = self.titleLabel?.text else { return }
        let attributedString = NSMutableAttributedString(string: text)
        //NSAttributedStringKey.foregroundColor : UIColor.blue
        attributedString.addAttribute(NSAttributedString.Key.underlineColor, value: self.titleColor(for: .normal)!, range: NSRange(location: 0, length: text.count))
        attributedString.addAttribute(NSAttributedString.Key.foregroundColor, value: self.titleColor(for: .normal)!, range: NSRange(location: 0, length: text.count))
        attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: NSRange(location: 0, length: text.count))
        self.setAttributedTitle(attributedString, for: .normal)
    }
}



extension UILabel {
    func underline() {
        if let textString = self.text {
            let attributedString = NSMutableAttributedString(string: textString)
            attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: NSRange(location: 0, length: attributedString.length - 1))
            attributedText = attributedString
        }
    }
}