Swift 4 Label attributes

Question

I'm moving from swift 3 to swift 4. I have UILabels that I am giving very specific text properties to the label. I'm getting an 'unexpectedly found nil while unwrapping optional value' error when strokeTextAttributes is being initialized. I'm totally lost to be frank.

In swift 3 the of strokeTextAttributes was [String : Any] but swift 4 threw errors until I changed it to what it is below.

let strokeTextAttributes = [
    NSAttributedStringKey.strokeColor.rawValue : UIColor.black,
    NSAttributedStringKey.foregroundColor : UIColor.white,
    NSAttributedStringKey.strokeWidth : -2.0,
    NSAttributedStringKey.font : UIFont.boldSystemFont(ofSize: 18)
    ] as! [NSAttributedStringKey : Any]


chevronRightLabel.attributedText = NSMutableAttributedString(string: "0", attributes: strokeTextAttributes)

Answer 1

@Larme's comment about the .rawValue not being needed is correct.

Also, you can avoid the force cast that crashes your code using explicit typing:

let strokeTextAttributes: [NSAttributedString.Key: Any] = [
    .strokeColor : UIColor.black,
    .foregroundColor : UIColor.white,
    .strokeWidth : -2.0,
    .font : UIFont.boldSystemFont(ofSize: 18)
]

This gets rid of the repetitive NSAttributedString.Key., too.