使用mask属性遮罩UIImageView之后添加遮罩边框

Question

I managed to get a mask for a UIImageView from a png using the .mask property but was wondering if there was any simple way to draw a border around the mask.

What it looks like:

Image

Code (UICollectionViewCell) :

lazy var maskingView: UIImageView = {

    let view = UIImageView()

    view.image = UIImage(named: "mask")
    return view
}()

lazy var profilePictureContainerView: UIImageView = {

    let containerView = UIImageView()

    containerView.backgroundColor = .black
    containerView.translatesAutoresizingMaskIntoConstraints = false
    return containerView
}()

override func layoutSubviews() {

    super.layoutSubviews()
    maskingView.frame = profilePictureContainerView.bounds
}

override init(frame: CGRect) {

    super.init(frame: frame)        
    profilePictureContainerView.mask = maskingView
    setUpViews()
}

setUpViews() is a func simply laying out a Collection View Cell and positioning the profilePictureContainerView inside it.

What I want to achieve

Put a border, say red, around the black shape (ie, the mask's "interior edge").

Any ideas ?

Answer 1

Did you try with layer?

maskingView.layer.borderWidth = 1 // Or any width 
maskingView.layer.borderColor = UIColor.red.cgColor