創(chuàng)建一個UILabel, 添加一下代碼

let path = UIBezierPath(roundedRect: btn.bounds, byRoundingCorners: [.topLeft, .bottomLeft], cornerRadii: CGSize(width: 13, height: 13))
let maskLayer = CAShapeLayer()
maskLayer.frame = btn.bounds
maskLayer.path = path.cgPath
btn.layer.mask = maskLayer

let gradientLayer = CAGradientLayer()
gradientLayer.colors = cgColors
gradientLayer.locations = [0, 1]
gradientLayer.frame = btn.bounds
gradientLayer.startPoint = CGPoint(x: 0, y: 0)
gradientLayer.endPoint = CGPoint(x: 1, y: 1)
btn.layer.insertSublayer(gradientLayer, at: 0)      

iOS12顯示正常, 有圓角、漸變、文字, 但是iOS13不顯示文字, 原因待查(感覺是layer層的問題)

解決辦法: 更換為 UIButton 即可.