UISegmentedControl TintColor to Gradient Color

I am trying to set UIsegmentedControl tint color for the selected segment to gradient color and I am unable to do it

I am trying to follow this article https://www.bethedev.com/2019/02/set-gradient-tint-color-for-segmented.html

Trying to use this code:

segmentedControl.setTitleTextAttributes([NSAttributedString.Key.foregroundColor:UIColor.white],for: UIControl.State.normal)
        segmentedControl.setTitleTextAttributes([NSAttributedString.Key.foregroundColor:UIColor.white],for: UIControl.State.selected)  

fileprivate func updateGradientBackground() {
        let sortedViews = segmentedControl.subviews.sorted( by: { $0.frame.origin.x < $1.frame.origin.x } )
        for (_, view) in sortedViews.enumerated() {
//            let gradientImage = gradient(size: segmentedControl.frame.size, color: [UIColor.cyan,UIColor.blue])!
            view.backgroundColor = UIColor(patternImage: UIImage(named: "segmentedRectangle.png")!)
            view.tintColor = UIColor.clear
        }
    }

I am expecting only one segment to be of the segmentedRectangle.png image color but it is displaying on the entire segmented control like this.

Try this code, I put comments on relevant parts. Let me know if you need more explanation.

 let segmentedControl: UISegmentedControl = {
       let view =  UISegmentedControl(items: ["Pounds", "Kilograms"])
        view.selectedSegmentIndex = 0
        view.tintColor = .black
        view.backgroundColor = .white
        view.frame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width - 40, height: 20)
        /// Gradient
        let gradient = CAGradientLayer()
        gradient.frame =  CGRect(x: 0, y: 0, width:  UIScreen.main.bounds.width - 40, height: 20)
        let leftColor = UIColor.red
        let rightColor = UIColor.purple
        gradient.colors = [leftColor.cgColor, rightColor.cgColor]
        gradient.startPoint = CGPoint(x: 0, y: 0.5)
        gradient.endPoint = CGPoint(x: 1.0, y: 0.5)
        /// Create gradient image
        UIGraphicsBeginImageContext(gradient.frame.size)
        gradient.render(in: UIGraphicsGetCurrentContext()!)
        let segmentedControlImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        // Normal Image
        let rect: CGRect = CGRect(x: 0, y: 0, width: 1, height: 1)
        UIGraphicsBeginImageContext(rect.size);
        let context:CGContext = UIGraphicsGetCurrentContext()!;
        context.setFillColor(UIColor.white.cgColor)
        context.fill(rect)
        let normalImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        /// Set segmentedControl image
        view.setBackgroundImage(normalImage, for: .normal, barMetrics: .default)
        view.setBackgroundImage(segmentedControlImage, for: .selected, barMetrics: .default)
        return view
    }()

Usage: On your ViewDidLoad set navigationItem title view as your segmented control like so:-

self.navigationItem.titleView = segmentedControl

I think with few modifications/custominization you can get want you want, Cheers :)

StoryBoard/InterfaceBuilder

Just call this inside your ViewDidLoad and pass your outlet name on the function call: -

   func configureSegementedControl(segmentedControl: UISegmentedControl) {
        segmentedControl.selectedSegmentIndex = 0
        segmentedControl.tintColor = .black
        segmentedControl.backgroundColor = .white
        segmentedControl.frame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width - 40, height: 20)
        /// Gradient
        let gradient = CAGradientLayer()
        gradient.frame =  CGRect(x: 0, y: 0, width:  UIScreen.main.bounds.width - 40, height: 20)
        let leftColor = UIColor.red
        let rightColor = UIColor.purple
        gradient.colors = [leftColor.cgColor, rightColor.cgColor]
        gradient.startPoint = CGPoint(x: 0, y: 0.5)
        gradient.endPoint = CGPoint(x: 1.0, y: 0.5)
        /// Create gradient image
        UIGraphicsBeginImageContext(gradient.frame.size)
        gradient.render(in: UIGraphicsGetCurrentContext()!)
        let segmentedControlImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        // Normal Image
        let rect: CGRect = CGRect(x: 0, y: 0, width: 1, height: 1)
        UIGraphicsBeginImageContext(rect.size);
        let context:CGContext = UIGraphicsGetCurrentContext()!;
        context.setFillColor(UIColor.white.cgColor)
        context.fill(rect)
        let normalImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        /// Set segmentedControl image
        segmentedControl.setBackgroundImage(normalImage, for: .normal, barMetrics: .default)
        segmentedControl.setBackgroundImage(segmentedControlImage, for: .selected, barMetrics: .default)
    }