ios - UIButton backgroundRect(forBounds :) not being called

Question

我有一个自定义的六边形按钮，我想禁用背景颜色，这样它就不会在六边形本身周围创建方形形状。我正在使用 backgroundRect(forBounds:) 方法来覆盖背景的矩形。这是完整的实现:

class HexaButton : UIButton {
    var shape : CAShapeLayer!
    func setup() {
        if shape == nil {
            shape = CAShapeLayer()
            shape.fillColor = self.backgroundColor?.cgColor
            shape.strokeColor = UIColor.cyan.cgColor
            shape.lineWidth = 5.0
            self.backgroundColor = UIColor.yellow
            self.layer.addSublayer(shape)
        }
        let side : CGFloat =  6
        let r =  frame.height/side
        shape.path = ShapeDrawer.polygonPath(x: frame.width/2, y: frame.height/2, radius: r, sides: Int(side), pointyness: side/2.0)

    }
    override func backgroundRect(forBounds bounds: CGRect) -> CGRect {
        return .zero
    }
    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setup()
    }
    override func layoutSubviews() {
        super.layoutSubviews()
        setup()
    }
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        if shape?.path?.contains(point) == true {
            return self
        } else {
            return nil
        }
    }
}

由于某种未知的原因，backgroundRect(forBounds:) 未被调用。有什么想法吗？

Answer 1

您需要设置UIButton 的backgroundImage 属性，backgroundRect 方法将被调用。