swift CALayer的+帮手

Posted 2021-05-19

import UIKit

extension CAGradientLayer {
    convenience init(colors: [CGColor]?, locations: [NSNumber]? = nil, startPoint: CGPoint = CGPoint(x: 0.5, y: 0), endPoint: CGPoint = CGPoint(x: 0.5, y: 1.0), frame: CGRect = .zero) {
        self.init()
        self.frame = frame
        self.colors = colors
        self.locations = locations
        self.startPoint = startPoint
        self.endPoint = endPoint
    }
}

//to define later on some custom layers
class OverlayLayer: CAGradientLayer {
    override func layoutSublayers() {
        super.layoutSublayers()
        self.colors = [UIColor.red.cgColor,
                       UIColor.yellow.cgColor,
                       UIColor.green.cgColor]
    }
}