ios - uiviewcontroller uiview 添加渐变层

Question

我正在尝试为 UIViewController 的背景创建一个简单的渐变。我的代码是:

    let gradientLayer = CAGradientLayer()
    gradientLayer.frame = view.bounds
    let bottomColor = UIColor(hue: 208 / 360, saturation: 82 / 100, brightness: 0.9, alpha: 1)
    let topColor = UIColor(hue: 208 / 360, saturation: 41 / 100, brightness: 0.9, alpha: 1)
    gradientLayer.colors = [bottomColor, topColor]
    gradientLayer.startPoint = CGPoint(x: 0.5, y: 0.1)
    gradientLayer.endPoint = CGPoint(x: 0.5, y: 0.0)

    view.layer.addSublayer(gradientLayer)

渐变不显示。当我查看 View 调试器时，我没有看到它。我检查了 View 的框架，它看起来不错

x: 0, y:0, width: 375, height: 667

我也尝试了 view.layer.insert at 方法，但没有用。如果我这样做

view.layer.backgroundColor.orange

然后我确实看到了橙色背景。我错过了什么吗？

Answer 1

改变

gradientLayer.colors = [bottomColor, topColor]

到

gradientLayer.colors = [bottomColor.cgColor, topColor.cgColor]