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

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)
    }
}

Answer 2

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)

Answer 3

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.

Answer 4

Swift 5 / Xcode 11

  @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) 
    }

Answer 5

@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
        }
    }
}

Answer 6

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
]