设置 CALayer 的阴影如何打破 AutoLayout 约束？

Question

我有 cell 的 imageView 阴影自定义：

override func layoutSubviews() {
    moviePosterImageView.layer.shadowOffset = .zero
    moviePosterImageView.layer.shadowColor = UIColor.black.cgColor
    moviePosterImageView.layer.shadowRadius = 5
    moviePosterImageView.layer.shadowOpacity = 1
    moviePosterImageView.layer.masksToBounds = false
    moviePosterImageView.layer.shadowPath = UIBezierPath(rect: moviePosterImageView.bounds).cgPath
}

但它打破了 imageView 的大小和限制。没有影子效果还不错

Answer 1

在另一个 swift 文件中使用此代码并在故事板或 xib 中轻松设置阴影

extension UIView {

@IBInspectable
var cornerRadius: CGFloat {
    get {
        return layer.cornerRadius
    }
    set {
        layer.cornerRadius = newValue
    }
}

@IBInspectable
var borderWidth: CGFloat {
    get {
        return layer.borderWidth
    }
    set {
        layer.borderWidth = newValue
    }
}

@IBInspectable
var borderColor: UIColor? {
    get {
        if let color = layer.borderColor {
            return UIColor(cgColor: color)
        }
        return nil
    }
    set {
        if let color = newValue {
            layer.borderColor = color.cgColor
        } else {
            layer.borderColor = nil
        }
    }
}

@IBInspectable
var shadowRadius: CGFloat {
    get {
        return layer.shadowRadius
    }
    set {
        layer.shadowRadius = newValue
    }
}

@IBInspectable
var shadowOpacity: Float {
    get {
        return layer.shadowOpacity
    }
    set {
        layer.shadowOpacity = newValue
    }
}

@IBInspectable
var shadowOffset: CGSize {
    get {
        return layer.shadowOffset
    }
    set {
        layer.shadowOffset = newValue
    }
}

@IBInspectable
var shadowColor: UIColor? {
    get {
        if let color = layer.shadowColor {
            return UIColor(cgColor: color)
        }
        return nil
    }
    set {
        if let color = newValue {
            layer.shadowColor = color.cgColor
        } else {
            layer.shadowColor = nil
        }
    }
  }
}

Answer 2

But it breaks imageView sizes and constraints.

是的，因为你忘了说

override func layoutSubviews() {
    super.layoutSubviews() // important

由于自动布局发生在layoutSubviews，如果您不调用super，您将阻止它运行。

设置 CALayer 的阴影如何打破 AutoLayout 约束？

How setting up shadow of the CALayer breaks AutoLayout constraints?

calayer

ios

autolayout

swift