How to draw a text string using Core Graphics

Swift version: 5.2

Paul Hudson @twostraws May 28th 2019

To draw text in Core Graphics is trivial because every Swift string has a built-in draw(with:) method that takes an array of attributes and a position and size. There is, like always, some Core Graphics set up work to do, but this next code snippet is a complete example you can re-use easily:

let renderer = UIGraphicsImageRenderer(size: CGSize(width: 512, height: 512))
let img = renderer.image { ctx in
    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.alignment = .center

    let attrs = [NSAttributedString.Key.font: UIFont(name: "HelveticaNeue-Thin", size: 36)!, NSAttributedString.Key.paragraphStyle: paragraphStyle]

    let string = "How much wood would a woodchuck\nchuck if a woodchuck would chuck wood?"
    string.draw(with: CGRect(x: 32, y: 32, width: 448, height: 448), options: .usesLineFragmentOrigin, attributes: attrs, context: nil)
}