mohacs mohacs - 4 months ago 14x
Swift Question

How to change Corner Radius of NSView in Swift Language

changing corner radius of NSView should be pretty straight forward however i am getting error message "fatal error: Can't unwrap Optional.None". is there a chance i am doing this with 10.9 not 10.10 and this is happening due framework differences? or the code is wrong.

class aRoundView: NSView {

let cornerRad = 5.0

init(frame: NSRect) {
super.init(frame: frame)

self.layer.cornerRadius = cornerRad

override func drawRect(dirtyRect: NSRect)


calling it in

func applicationDidFinishLaunching(aNotification: NSNotification?) {

let aView = mainViewTest(frame: NSMakeRect(0, 0, 100, 100))


actually it is not just that. any iteration with self.layer gives same result, backgroundcolor etc.


That is because self.layer is an Optnional value, which is currently not set. Add self.wantsLayer = true before self.layer.cornerRadius, to make sure a proper layer exists.

init(frame: NSRect) {
    super.init(frame: frame)
    self.wantsLayer = true
    self.layer.cornerRadius  = cornerRad