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

Here you can add an underline and bold face too. You can just add an extention in your swift class file

Here is the extention (Swift 4 updated)

extension NSMutableAttributedString {
 @discardableResult func bold(_ text:String) -> NSMutableAttributedString {

      let attrs : [NSAttributedStringKey : Any] = [
        NSAttributedStringKey.font : UIFont(name: "Montserrat-Bold", size: 12)!,
        NSAttributedStringKey.foregroundColor : UIColor.white,
        NSAttributedStringKey.underlineStyle : NSUnderlineStyle.styleSingle.rawValue]
    let boldString = NSMutableAttributedString(string: text, attributes: attrs)
    self.append(boldString)
    return self
 }

 @discardableResult func normal(_ text:String)->NSMutableAttributedString {
      let attrs : [NSAttributedStringKey : Any] = [
        NSAttributedStringKey.font : UIFont(name: "Montserrat-Regular", size: 12)!,
        NSAttributedStringKey.foregroundColor : UIColor.white
    ]
    let normal =  NSAttributedString(string: text,  attributes:attrs)
    self.append(normal)
    return self
 }

}

You can use it like this:

let FormattedText = NSMutableAttributedString()
      FormattedText
           .normal("By signing in, you agree with our ")
           .bold("Terms of Service")

yourLabel.attributedText = FormattedText

and the Result will be display like this

Answer 2

May not be the best approach but I made an example to use it with a separated class and make only a one line call to get the text.

Here is my class:

import Foundation
import UIKit

enum AttributedTextsType {
    case underlined
    case bold
    case boldUnderlined
}

class AttributedTexts {
    private static func underlinedText(color: UIColor, size: CGFloat) -> [NSAttributedString.Key : Any] {
    let attrs = [
        NSAttributedString.Key.font : UIFont.systemFont(ofSize: size),
        NSAttributedString.Key.foregroundColor : color,
        NSAttributedString.Key.underlineStyle : 1] as [NSAttributedString.Key : Any]
    return attrs
    }

    private static func getAttibute(type: AttributedTextsType, color: UIColor, size: CGFloat) -> [NSAttributedString.Key : Any] {
        var attributes: [NSAttributedString.Key : Any]!
        switch type {
        case .underlined:
            attributes = AttributedTexts.underlinedText(color: color, size: size)
            break
        case .bold:
            attributes = AttributedTexts.underlinedText(color: color, size: size)
            break
        case .boldUnderlined:
            attributes = AttributedTexts.underlinedText(color: color, size: size)
            break
        }
        return attributes
    }

    static func set(string: String, color: UIColor, type: AttributedTextsType, size: CGFloat = 19.0) -> NSMutableAttributedString {
        let attributes = getAttibute(type: type, color: color, size: size)
        let attributedString = NSMutableAttributedString(string:"")
        let buttonTitleStr = NSMutableAttributedString(string: string, attributes: attributes)
        attributedString.append(buttonTitleStr)
        return attributedString
    }
}

Usage let attributedString = AttributedTexts.set(string: "Skip", color: .white, type: .underlined, size: 19.0)

Best regards