Resolved CAGradientLayer Rendering XCode Beta 3

[slooksterPSV]

I’ve been learning Swift and iOS programming and one of the challenges is to add a CAGradientLayer to the view.

I’ve created sub views and get colors to show up but I can’t get CAGradientLayer to appear on my view. In view did load I can get flat color views but not gradients. What am I doing wrong? Am I not adding it to the view properly?

Thanks.

 

[slooksterPSV]

Really? The reason it wasn't working is because I wasn't using the cgColor for the color values. Wow, okay, good to know.

It's fixed now.

import UIKit

class ViewController: UIViewController {

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

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        
        let newView = UIView()
        newView.frame = view.frame
        
        let gradient = CAGradientLayer()
        gradient.frame = view.frame
        gradient.colors = [UIColor.blue.cgColor, UIColor.yellow.cgColor, UIColor.red.cgColor]
        newView.layer.addSublayer(gradient)
        
        view.insertSubview(newView, at: 0)
    }
}

 

[casperes1996]

Instead of doing .cgColor you could also just use the CGColor class directly. - UIColor is built on top of CGColor, so CGColor has no idea that UIColor exists, but UIColor knows about CGColor since CG is below it. CgColors are in a way more primitive types