Swift 4 Cannot convert value of type '[String : AnyObject]?' to expected argument type '[NSAttributedStringKey : Any]?'

Question

I have just updated to Xcode 9 and converted my app from swift 3 to swift 4. I have graphs which use strings to label the axes and other variables. So I have a moneyAxisStri

Answer 1

It's a type mismatch: [String : AnyObject] is clearly not [NSAttributedStringKey : Any]

⌥-click on NSAttributedStringKey to see the declaration.

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The solution is to declare attributes as

var attributes = [NSAttributedStringKey : Any]()

to remove the down cast

 ..., withAttributes: attributes)

and to write simply

attributes = [.foregroundColor: fieldColor,
              .font: fieldFont!,
              .paragraphStyle: style]