UIAppearance and Rounded Borders in Swift

Question

So I'm fairly new to the whole UIAppearance approach to doing things, and doing it with swift. Hurray for not a ton of documentation out there.

I'm trying to set my border radius through UIAppearance with something along the lines of:

CircleButton.appearance.roundBorderRadius = 9

My CircleButton class implementation:

public class CircleButton : UIButton{
     @nonobjc var roundBorderRadius: CGFloat? {
        get { return self.layer.cornerRadius }
        set {
            self.layer.cornerRadius = newValue!
        }
    }
}

And I hook everything up in Storyboard to a ViewController that contains a CircleButton. No Compilation or Build errors.

However, at runtime I'm getting a:

"Thread 1: EXC_BAD_ACCESS" error on:

CircleButton.appearance.roundBorderRadius = 9

Any advice?

Answer 1

Remove @nonobjc and add dynamic, then change the type from CGFloat? to CGFloat and remove the ! after newValue in the setter, like so:

public class CircleButton: UIButton {

    dynamic var roundBorderRadius: CGFloat {
        get { 
            return layer.cornerRadius
        }

        set {
            layer.cornerRadius = newValue
        }
    }
}