Question

我正在尝试自己的自定义UIButton。我继承了UIButton类，并尝试添加一些功能，这是我的代码：

import UIKit


class CustomButton: UIButton {

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
        setGradientBackground()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        fatalError("init(coder:) has not been implemented")
    }

    private func setup() {
        layer.cornerRadius = 8
    }

    private func setGradientBackground() {

        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = bounds
        gradientLayer.colors = [UIColor.yellow.cgColor, UIColor.blue.cgColor]
        gradientLayer.locations = [0.0, 1.0]
        gradientLayer.startPoint = CGPoint(x: 1.0, y: 1.0)
        gradientLayer.endPoint = CGPoint(x: 0.0, y: 0.0)

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

我将其链接到我的IBOutlet：

@IBOutlet weak var myButton: CustomButton!

没有任何内容！

Answer 1

如果要在情节提要中添加按钮，则调用的初始化程序为init?(coder aDecoder: NSCoder)，而不是init(frame: CGRect)，因此需要添加…

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    setup()
    setGradientBackground()
}

Answer 2

使用func awakeFromNib()：

class CustomButton: UIButton {

    override func awakeFromNib() {
        super.awakeFromNib()

        setup()
        setGradientBackground()
    }

    private func setup() {
        layer.cornerRadius = 8
    }

    private func setGradientBackground() {

        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = bounds
        gradientLayer.colors = [UIColor.yellow.cgColor, UIColor.blue.cgColor]
        gradientLayer.locations = [0.0, 1.0]
        gradientLayer.startPoint = CGPoint(x: 1.0, y: 1.0)
        gradientLayer.endPoint = CGPoint(x: 0.0, y: 0.0)

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

自定义UIButton子类

2 个答案: