Outline UILabel text in UILabel Subclass

问题:

I'm trying hard to find a way to simply add an outline/stroke/contour to my UILabel text. Talking about a stroke around the letters of the text not around the background of a UILabel.

I'm using swift 3 and I'd like to outline my text directly into my subclass: UILabel.

I found multiple answers suggesting this way to do things :

let strokeTextAttributes = [
        NSStrokeColorAttributeName : UIColor.black,
        NSForegroundColorAttributeName : UIColor.white,
        NSStrokeWidthAttributeName : -4.0,
        NSFontAttributeName : UIFont.boldSystemFont(ofSize: 30)
    ]

    self.attributedText = NSMutableAttributedString(string: self.text!, attributes: strokeTextAttributes)

But the thing is that it doesn't work. My text is still the same with no outline...

Could anyone help me here ? That would be a great thing :)

Thanks a lot. Cheers guys.

回答1:

Here you have class with implementation, copy and paste to playgrond for test:

    class StrokedLabel: UILabel {

        var strockedText: String = "" {
            willSet(newValue) {
                let strokeTextAttributes = [
                    NSStrokeColorAttributeName : UIColor.black,
                    NSForegroundColorAttributeName : UIColor.white,
                    NSStrokeWidthAttributeName : -4.0,
                    NSFontAttributeName : UIFont.boldSystemFont(ofSize: 30)
                    ] as [String : Any]

                let customizedText = NSMutableAttributedString(string: newValue,
                                                               attributes: strokeTextAttributes)


                attributedText = customizedText
            }
        }
    }


//////////// PLAYGROUND IMPLEMENTATION PART /////////
    let text = "Stroked text"

// UILabel subclass initialization
    let label = StrokedLabel(frame: CGRect(x: 0, y: 0, width: 200, height: 50))
// simple assign String to 'strockedText' property to see the results
    label.strockedText = text

    label.backgroundColor = UIColor.white


    label

Maybe refactoring for this class will be welcomed, but should work for you at this form

As you can see usage is very convenient.