方向转换后UIView中的渐变

Question

我拥有UIView的扩展名以应用渐变：

    extension UIView {

    func applyGradient(colors: [CGColor]) {

        self.backgroundColor = nil
        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = self.bounds // Here new gradientLayer should get actual UIView bounds
        gradientLayer.cornerRadius = self.layer.cornerRadius
        gradientLayer.colors = colors
        gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.0)
        gradientLayer.endPoint = CGPoint(x: 1.0, y: 1.0)
        gradientLayer.masksToBounds = true

        self.layer.insertSublayer(gradientLayer, at: 0)
    }
}

在我的UIView子类中，我正在创建所有视图并设置约束：

private let btnSignIn: UIButton = {
    let btnSignIn = UIButton()

    btnSignIn.setTitle("Sing In", for: .normal)
    btnSignIn.titleLabel?.font = UIFont(name: "Avenir Medium", size: 35)

    btnSignIn.layer.cornerRadius = 30
    btnSignIn.clipsToBounds = true
    btnSignIn.translatesAutoresizingMaskIntoConstraints = false

    return btnSignIn
}()

override init(frame: CGRect) {
    super.init(frame: frame)
    addSubViews()
}

required init?(coder: NSCoder) {
    super.init(coder: coder)
    addSubViews()
}

func addSubViews() {
    self.addSubview(imageView)
    self.addSubview(btnSignIn)
    self.addSubview(signUpstackView)
    self.addSubview(textFieldsStackView)
    setConstraints()
}

我重写了layoutSubviews函数，每次更改视图边界时都会调用该函数（包括定向转换），我在其中调用applyGradient。

override func layoutSubviews() {
    super.layoutSubviews()
    btnSignIn.applyGradient(colors: [Colors.ViewTopGradient, Colors.ViewBottomGradient])
}

问题在于，由于某些原因，方向转换梯度应用错误后...

请查看屏幕截图

我在这里想念什么？

Answer 1

@IBDesignable
public class RoundedGradientButton: UIButton {

    static public override var layerClass: AnyClass { CAGradientLayer.self }
    private var gradientLayer: CAGradientLayer      { layer as! CAGradientLayer }

    @IBInspectable var startColor: UIColor = .blue  { didSet { updateColors() } }
    @IBInspectable var endColor: UIColor = .red     { didSet { updateColors() } }

    override public init(frame: CGRect = .zero) {
        super.init(frame: frame)
        configure()
    }

    required public init?(coder: NSCoder) {
        super.init(coder: coder)
        configure()
    }

    override public func layoutSubviews() {
        super.layoutSubviews()
        layer.cornerRadius = min(bounds.height, bounds.width) / 2
    }
}

private extension RoundedGradientButton {
    func configure() {
        gradientLayer.startPoint = CGPoint(x: 0, y: 0)
        gradientLayer.endPoint = CGPoint(x: 1, y: 1)
        updateColors()

        titleLabel?.font = UIFont(name: "Avenir Medium", size: 35)
    }

    func updateColors() {
        gradientLayer.colors = [startColor.cgColor, endColor.cgColor]
    }
}

以上，我将layerClass设置为layerClass，这样操作系统就可以为我更新该层的边界。我需要做的就是确保正确更新角半径。