Underline button text in Swift

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 myBtn: UIButton!

I created a function called on the touchUpInside event of this button:

var attributedString = NSMutableAttributedString(string:"new text")
    var attrs = [
        NSFontAttributeName : UIFont.systemFontOfSize(19.0),
        NSForegroundColorAttributeName : UIColor.redColor()
    ]
    var gString = NSMutableAttributedString(string:"g", attributes:attrs)
    attributedString.appendAttributedString(gString)
    
    myBtn.titleLabel?.attributedText = attributedString;

But still no result. Also I need to know how to access the underline attribute. Text, size and color stay the same.

Swift 5 / Xcode 12/13

  @IBOutlet weak var myButton: UIButton!
   
  let yourAttributes: [NSAttributedString.Key: Any] = [
      .font: UIFont.systemFont(ofSize: 14),
      .foregroundColor: UIColor.blue,
      .underlineStyle: NSUnderlineStyle.single.rawValue
  ] // .double.rawValue, .thick.rawValue
         
  
  override func viewDidLoad() {
     super.viewDidLoad()
    
     let attributeString = NSMutableAttributedString(
        string: "Your button text",
        attributes: yourAttributes
     )
     myButton.setAttributedTitle(attributeString, for: .normal)
  }

Swift 4 / Xcode 9

  @IBOutlet weak var myButton: UIButton!
   
  let yourAttributes: [NSAttributedStringKey: Any] = [
      NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14),
      NSAttributedStringKey.foregroundColor: UIColor.blue,
      NSAttributedStringKey.underlineStyle: NSUnderlineStyle.styleSingle.rawValue
  ] // .styleDouble.rawValue, .styleThick.rawValue, .styleNone.rawValue             
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    let attributeString = NSMutableAttributedString(
      string: "Your button text",
      attributes: yourAttributes
    )
    myButton.setAttributedTitle(attributeString, for: .normal)
  }

Swift 3 / Xcode 8

  @IBOutlet weak var myButton: UIButton!

  let yourAttributes: [String: Any] = [
      NSFontAttributeName: UIFont.systemFont(ofSize: 14),
      NSForegroundColorAttributeName: UIColor.white,
      NSUnderlineStyleAttributeName: NSUnderlineStyle.styleSingle.rawValue
  ] // .styleDouble.rawValue, .styleThick.rawValue, .styleNone.rawValue             

   override func viewDidLoad() {
      super.viewDidLoad()

      let attributeString = NSMutableAttributedString(
        string: "Your button text",
        attributes: yourAttributes
      )        
      myButton.setAttributedTitle(attributeString, for: .normal) 
    }

Here you go, just tested it. (works in xCode 7 Beta at least)

@IBOutlet weak var yourButton: UIButton!

var attrs = [
NSFontAttributeName : UIFont.systemFontOfSize(19.0),
NSForegroundColorAttributeName : UIColor.redColor(),
NSUnderlineStyleAttributeName : 1]

var attributedString = NSMutableAttributedString(string:"")

override func viewDidLoad() {
  super.viewDidLoad()

  let buttonTitleStr = NSMutableAttributedString(string:"My Button", attributes:attrs)
  attributedString.appendAttributedString(buttonTitleStr)
  yourButton.setAttributedTitle(attributedString, forState: .Normal)
}

StoryBoard: If you want to Underline text from storyBoard.

• Select button or label title as Attributed.
• Select range of text which you want to underline.
• Right click and choose Font then select underline.

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
        }
    }
}

Based on some of previous answers I decide to make a class that can be easy implemented into your apps

Swift 4

import UIKit

class UnderlineTextButton: UIButton {

override func setTitle(_ title: String?, for state: UIControlState) {
    super.setTitle(title, for: .normal)
    self.setAttributedTitle(self.attributedString(), for: .normal)
}

private func attributedString() -> NSAttributedString? {
    let attributes : [NSAttributedStringKey : Any] = [
        NSAttributedStringKey.font : UIFont.systemFont(ofSize: 19.0),
        NSAttributedStringKey.foregroundColor : UIColor.red,
        NSAttributedStringKey.underlineStyle : NSUnderlineStyle.styleSingle.rawValue
    ]
    let attributedString = NSAttributedString(string: self.currentTitle!, attributes: attributes)
    return attributedString
  }
}

From code I call it on such a way button.setTitle(author, for: .normal)

Thanks for posting your code, it wasn't clear that you knew how to create an attributed string at all.

This should work:

var attrs = [
    NSFontAttributeName : UIFont.systemFontOfSize(19.0),
    NSForegroundColorAttributeName : UIColor.redColor(),
    NSUnderlineStyleAttributeName : NSUnderlineStyle.StyleSingle.rawValue
]

Swift 4 version:

var attrs : [NSAttributedStringKey : Any] = [
    NSAttributedStringKey.font : UIFont.systemFont(ofSize: 19.0),
    NSAttributedStringKey.foregroundColor : UIColor.red,
    NSAttributedStringKey.underlineStyle : NSUnderlineStyle.styleSingle.rawValue
]

@ShlomoKoppel answer in Swift 4.2

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 underlineMyText() {
        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
        }
    }
}

Here is done on the storyboard. (Xcode 9.1)

1. Select the Button object in your view.
2. Open Fonts Settings

3. Select Single Underline

4. Type your text, press [Enter]

This is my solution. And to be honest you probably need this more than one place, so let's create an extension. This is swift 5.0 Cheers :)

extension UIButton {
    func underline() {
        guard let title = self.titleLabel else { return }
        guard let tittleText = title.text else { return }
        let attributedString = NSMutableAttributedString(string: (tittleText))
        attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: NSRange(location: 0, length: (tittleText.count)))
        self.setAttributedTitle(attributedString, for: .normal)
    }
}

And you can use it like this.

    override func viewDidLoad() {
     super.viewDidLoad()
     button.underline()
}

• Swift 5.2.4
• Xcode 11.5

let attributes: [NSAttributedString.Key : Any] = [
NSAttributedString.Key.underlineStyle: 1,
NSAttributedString.Key.font: UIFont.systemFont(ofSize: 13),
NSAttributedString.Key.foregroundColor: UIColor.systemGray3
]

let attributedString = NSMutableAttributedString(string: "Text here", attributes: attributes)
button.setAttributedTitle(NSAttributedString(attributedString: attributedString), for: .normal)

A modified version of @shlomo-koppel answer for button title, It will work if you set/change button title programmatically (like in my case I used localization)

extension UIButton {
    func underline() {
        guard let text = self.currentTitle else { return }
        let attributedString = NSMutableAttributedString(string: text)
        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)
    }
}

For swift 5

var attrs : [NSAttributedString.Key : Any] = [
    NSAttributedString.Key.font : UIFont.systemFont(ofSize: 19.0),
    NSAttributedString.Key.foregroundColor : UIColor.blue,
    NSAttributedString.Key.underlineStyle : NSUnderlineStyle.styleSingle.rawValue
]
    

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

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