iOS NSAttributedString on UIButton

Question

I\'m using iOS 6, so attributed strings should be easy to use, right? Well... not so much.

What I want to do:

Using a custom subclass of

Answer 1

With Swift 5.1 and iOS 13.1, you can use the UIButton subclass implementation below in order to solve your problem:

import UIKit

class CustomButton: UIButton {

    required init(title: String, subtitle: String) {
        super.init(frame: CGRect.zero)

        let style = NSMutableParagraphStyle()
        style.alignment = NSTextAlignment.center
        style.lineBreakMode = NSLineBreakMode.byWordWrapping

        let titleAttributes: [NSAttributedString.Key : Any] = [
            NSAttributedString.Key.foregroundColor: UIColor.label,
            NSAttributedString.Key.underlineStyle : NSUnderlineStyle.single.rawValue,
            NSAttributedString.Key.font : UIFont.preferredFont(forTextStyle: UIFont.TextStyle.largeTitle),
            NSAttributedString.Key.paragraphStyle : style
        ]
        let subtitleAttributes = [
            NSAttributedString.Key.foregroundColor: UIColor.label,
            NSAttributedString.Key.font : UIFont.preferredFont(forTextStyle: UIFont.TextStyle.body),
            NSAttributedString.Key.paragraphStyle : style
        ]

        let attributedString = NSMutableAttributedString(string: title, attributes: titleAttributes)
        attributedString.append(NSAttributedString(string: "\n"))
        attributedString.append(NSAttributedString(string: subtitle, attributes: subtitleAttributes))

        setAttributedTitle(attributedString, for: UIControl.State.normal)
        titleLabel?.numberOfLines = 0
        titleLabel?.lineBreakMode = NSLineBreakMode.byWordWrapping
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

Usage:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let button = CustomButton(title: "Title", subtitle: "Subtitle")
        button.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(button)

        let horizontalConstraint = button.centerXAnchor.constraint(equalTo: view.centerXAnchor)
        let verticalConstraint = button.centerYAnchor.constraint(equalTo: view.centerYAnchor)
        NSLayoutConstraint.activate([horizontalConstraint, verticalConstraint])
    }

}

---

As an alternative if you really need a button of type system, you may use the following code:

import UIKit

extension UIButton {

    static func customSystemButton(title: String, subtitle: String) -> UIButton {
        let style = NSMutableParagraphStyle()
        style.alignment = NSTextAlignment.center
        style.lineBreakMode = NSLineBreakMode.byWordWrapping

        let titleAttributes: [NSAttributedString.Key : Any] = [
            NSAttributedString.Key.underlineStyle : NSUnderlineStyle.single.rawValue,
            NSAttributedString.Key.font : UIFont.preferredFont(forTextStyle: UIFont.TextStyle.largeTitle),
            NSAttributedString.Key.paragraphStyle : style
        ]
        let subtitleAttributes = [
            NSAttributedString.Key.font : UIFont.preferredFont(forTextStyle: UIFont.TextStyle.body),
            NSAttributedString.Key.paragraphStyle : style
        ]

        let attributedString = NSMutableAttributedString(string: title, attributes: titleAttributes)
        attributedString.append(NSAttributedString(string: "\n"))
        attributedString.append(NSAttributedString(string: subtitle, attributes: subtitleAttributes))

        let button = UIButton(type: UIButton.ButtonType.system)
        button.setAttributedTitle(attributedString, for: UIControl.State.normal)
        button.titleLabel?.numberOfLines = 0
        button.titleLabel?.lineBreakMode = NSLineBreakMode.byWordWrapping

        return button
    }

}

Usage:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let button = UIButton.customSystemButton(title: "Title", subtitle: "Subtitle")
        button.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(button)

        let horizontalConstraint = button.centerXAnchor.constraint(equalTo: view.centerXAnchor)
        let verticalConstraint = button.centerYAnchor.constraint(equalTo: view.centerYAnchor)
        NSLayoutConstraint.activate([horizontalConstraint, verticalConstraint])
    }

}

---

The two screen shots below show the result display for the UIButton subclass (on the left) and for the system type button (on the right):