Attributed UIButtons

attributedbuttons.cs

using System;
using CoreGraphics;
using CoreText;
using Foundation;
using UIKit;

namespace RainbowButtons.iOS
{
    public partial class ViewController : UIViewController
    {
        public ViewController(IntPtr handle) : base(handle)
        {
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();

            //SetNormalTitle();
            //SetFancyTitle();
            SetRainbowTitle();
        }

        void SetNormalTitle()
        {
            Button.SetTitle("Ayup Lads", UIControlState.Normal);
        }

        void SetFancyTitle()
        {
            var normalTitle = new NSAttributedString("Click Here", new UIStringAttributes() { ForegroundColor = UIColor.Blue });
            var highlightedTitle = new NSAttributedString("I am clicked :D", new UIStringAttributes() { ForegroundColor = UIColor.Green });        

            Button.SetAttributedTitle(normalTitle, UIControlState.Normal);
            Button.SetAttributedTitle(highlightedTitle, UIControlState.Highlighted);
        }

        void SetRainbowTitle()
        {
            var rainbowTitle = new NSMutableAttributedString("Rainbow");
            rainbowTitle.AddAttribute(UIStringAttributeKey.ForegroundColor, UIColor.Red, new NSRange(0, 1));
            rainbowTitle.AddAttribute(UIStringAttributeKey.ForegroundColor, UIColor.Orange, new NSRange(1, 1));
            rainbowTitle.AddAttribute(UIStringAttributeKey.ForegroundColor, UIColor.Yellow, new NSRange(2, 1));
            rainbowTitle.AddAttribute(UIStringAttributeKey.ForegroundColor, UIColor.Green, new NSRange(3, 1));
            rainbowTitle.AddAttribute(UIStringAttributeKey.ForegroundColor, UIColor.Cyan, new NSRange(4, 1));
            rainbowTitle.AddAttribute(UIStringAttributeKey.ForegroundColor, UIColor.Blue, new NSRange(5, 1));
            rainbowTitle.AddAttribute(UIStringAttributeKey.ForegroundColor, UIColor.Purple, new NSRange(6, 1));

            Button.SetAttributedTitle(rainbowTitle, UIControlState.Normal);
        }
    }
}

attributedbuttons.swift

//
//  ViewController.swift
//  AttributedButton
//
//  Created by Alexander Duffell on 09/12/2020.
//

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var myButton: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
//        SetNormalTitle()
//        SetFancyTitle()
        SetRainbowTitle()
    }
    
    func SetNormalTitle() {
        myButton.setTitle("Ayup Lads", for: .normal)
    }
    
    func SetFancyTitle() {
        
        // .Selected
        let mySelectedAttributedTitle = NSAttributedString(string: "Click Here",
                                                           attributes: [NSAttributedString.Key.foregroundColor : UIColor.green])
        myButton.setAttributedTitle(mySelectedAttributedTitle, for: .highlighted)

        // .Normal
        let myNormalAttributedTitle = NSAttributedString(string: "Click Here",
                                                         attributes: [NSAttributedString.Key.foregroundColor : UIColor.blue])
        myButton.setAttributedTitle(myNormalAttributedTitle, for: .normal)
    }
    
    func SetRainbowTitle() {
        let rainbowTitle = NSMutableAttributedString(string: "Rainbow")
        rainbowTitle.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.red, range: _NSRange(location: 0, length: 1))
        rainbowTitle.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.orange, range: _NSRange(location: 1, length: 1))
        rainbowTitle.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.yellow, range: _NSRange(location: 2, length: 1))
        rainbowTitle.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.green, range: _NSRange(location: 3, length: 1))
        rainbowTitle.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.cyan, range: _NSRange(location: 4, length: 1))
        rainbowTitle.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.blue, range: _NSRange(location: 5, length: 1))
        rainbowTitle.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.purple, range: _NSRange(location: 6, length: 1))
        
        myButton.setAttributedTitle(rainbowTitle, for: .normal)
    }
}