Why properties tagged @IBInspectable is not working?

Question

I followed the tutorial here to create an inspectable and designable view. I just want to add border color, border width, and rounded border capability into the UIView.

I have been successful to show the properties. But doesn't matter what I set on the storyboard, the result is still like if they aren't there. There's no border, even though I've set the border to be 2 in width and black in color. It's not showing both on the storyboard and at the run time. I have set the border to be 2 width, but at run time, I print the border width value at didViewLoad, and the result is 0. What could be possibly wrong?

@IBDesignable extension view: UIView {

    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth;
        }
        set {
            layer.borderWidth = borderWidth;
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(CGColor: layer.borderColor!);
        }
        set {
            layer.borderColor = borderColor?.CGColor
        }
    }

}

And this doesn't work either:

@IBDesignable class BOView: UIView {

    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth;
        }
        set {
            layer.borderWidth = borderWidth;
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(CGColor: layer.borderColor!);
        }
        set {
            layer.borderColor = borderColor?.CGColor
        }
    }

}

Answer 1

Try using newValue instead of the real value.

For instance,

@IBInspectable var borderWidth: CGFloat {
    get {
        return layer.borderWidth
    }
    set {
        layer.borderWidth = newValue
    }
}

Chen, I do prefer the way you are doing it, but also note that what you are trying to do is possible from Storyboard directly without using IBDesignable. You can set the layer properties in User Defined Runtime Attributes.