制作 UIFont Black/Heavy 和斜体

Question

如何为标签设置字体 heavy AND italic?

来自 SO 的示例不起作用：

labelCurrentDate.font = UIFont(descriptor: UIFont.systemFont(ofSize: 32, weight: .black).fontDescriptor.withSymbolicTraits(.traitItalic)!, size: 32)

同样无效：

extension UIFont {
    static func systemFontItalic(size fontSize: CGFloat = 17.0, fontWeight: UIFont.Weight = .regular) -> UIFont {
        let font = UIFont.systemFont(ofSize: fontSize, weight: fontWeight)
        return UIFont(descriptor: font.fontDescriptor.withSymbolicTraits(.traitItalic)!, size: fontSize)
    }
}

编辑：

我的"real"代码：

@IBOutlet weak var labelCurrentDate: UILabel! {
    didSet {
        labelCurrentDate.font = UIFont(descriptor: UIFont.systemFont(ofSize: 32, weight: .black).fontDescriptor.withSymbolicTraits(.traitItalic)!, size: 32)
        labelCurrentDate.textColor = colorLightMainText
    }
}

我的结果：

如您所见，我的标签文字粗细不是 "black" - 这是正常的字体粗细，但我希望它是黑色的。

Answer 1

我是这样测试的：

let weights : [UIFont.Weight] = [
    .ultraLight, .thin, .light, .regular, 
    .medium, .semibold, .bold, .heavy, .black
]
var top : CGFloat = 25
for weight in weights {
    let desc = UIFont.systemFont(ofSize: 32).fontDescriptor.addingAttributes([
        UIFontDescriptor.AttributeName.traits: [
            UIFontDescriptor.TraitKey.weight: 
                weight.rawValue,
            UIFontDescriptor.TraitKey.symbolic: 
                UIFontDescriptor.SymbolicTraits.traitItalic.rawValue
        ]
    ])
    let lab = UILabel()
    lab.font = UIFont(descriptor: desc, size: 0)
    lab.text = "This is a test"
    lab.sizeToFit()
    lab.frame.origin = CGPoint(x: 20, y: top)
    self.view.addSubview(lab)
    top += lab.bounds.height + 8
}

这是我看到的：

所以在我看来，我们在斜体字体样式中获得了所有不同的粗细。

制作 UIFont Black/Heavy 和斜体

Making UIFont Black/Heavy and Italic

swift

xcode

uifont