UIButton的layer.cornerRadius删除按钮标题的可见性

Question

I have added a custom class for my buttons where I set corner radius (to save some code for multiple VCs) but once I set it, title from my buttons disappears. You can see I have a button title set and it worked ok before choosing a custom class.

Background of my button is the gray color with alpha. I have tried to play with the .isOpaque setting but got no luck getting the title back. Any idea what could cause this problem?

@IBDesignable class RoundedButton: UIButton {

    @IBInspectable var cornerRadius: CGFloat = 8

    override func layoutSubviews() {
        layer.cornerRadius = cornerRadius
    }
}

Edit: Solved! Thanks u/zombie for an explenation!

Answer 1

The title does not show because its frame was not updated.

To fix the layout you need to call super.layoutSubviews

override func layoutSubviews() {
    super.layoutSubviews()
    layer.cornerRadius = cornerRadius
}

Your approach might prevent any update of the radius outside of your variable.

here is a better way to do it:

@IBDesignable class RoundedButton: UIButton {

    private var defaultCornerRadius: CGFloat = 8

    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }

        set {
            layer.cornerRadius = newValue
        }
    }

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

        cornerRadius = defaultCornerRadius
    }

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

        cornerRadius = aDecoder.decodeObject(forKey: "cornerRadius") as? CGFloat ?? defaultCornerRadius
    }



    override func encode(with aCoder: NSCoder) {
        super.encode(with: aCoder)

        aCoder.encode(cornerRadius, forKey: "cornerRadius")
    }
}

Answer 2

You forget

override func layoutSubviews() {
    super.layoutSubviews()
    layer.cornerRadius = cornerRadius
}