How can i see with #designable this design on storyboard - swift

Question

I'm using masking.
My Code:
class ViewController: UIViewController {
#IBOutlet weak var firstImageView: UIImageView!
#IBOutlet weak var seconImageView: UIImageView!
let maskView = UIImageView()
let maskView2 = UIImageView()
override func viewDidLoad() {
super.viewDidLoad()
maskView.image = UIImage(named: "Up")
maskView2.image = UIImage(named: "Down")
firstImageView.mask = maskView
seconImageView.mask = maskView2
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
maskView.frame = firstImageView.bounds
maskView2.frame = seconImageView.bounds
}
}
UIImageView Code:
UIImageView class. I can't see this design. How can I do ? I added custom class but didn't work
#IBDesignable
class FirstImageView: UIImageView {
var maskkView: UIImageView!
override init(frame: CGRect) {
super.init(frame: frame)
layoutSubviews()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
layoutSubviews()
}
override func layoutSubviews() {
super.layoutSubviews()
maskkView.image = UIImage(named: "mask")
mask = maskkView
maskkView.frame = bounds
}
}
Storyboard:
Simulator:
How can i see with #designable this design on storyboard.

Answer 1

I added custom class but didn't work
I assure you that masking in layoutSubviews of an IBDesignable UIImageView does work. Example:
#IBDesignable
class MyImageView : UIImageView {
override func layoutSubviews() {
super.layoutSubviews()
let lay = CAShapeLayer()
lay.frame = self.bounds
lay.path = UIBezierPath(ovalIn: self.bounds).cgPath
self.layer.mask = lay
}
}
Result:
I suspect that the problem with your code is that you are attempting to load an image from the bundle with UIImage(named:) in your IBDesignable code; my guess is that that isn't going to work. IBDesignable code is just some stuff that runs at storyboard rendering time; it cannot behave as if it were truly the running app.