Question

我需要创建带有阴影的UIView，但是我只需要在右，左，下边缘阴影->上边缘没有阴影。有可能这样做吗？我尝试了不同的偏移量，但是没有达到目标。

Answer 1

像这样吗？

let yourView = UIView()
yourView.frame = CGRect(x: 50, y: 50, width: 100, height: 100)
yourView.backgroundColor = UIColor.blue // NEEDS A COLOR TO SHOW SHADOW
yourView.layer.shadowColor = UIColor.black.cgColor
yourView.layer.shadowOpacity = 1
yourView.layer.shadowOffset = CGSize.zero
yourView.layer.shadowRadius = 10
self.view.addSubview(yourView)

Answer 2

我个人认为，克服后一个问题的最佳方法是创建UIView的@IBDesignable扩展并声明@IBInspectable属性，如下所述

public extension UIView {

    // MARK: - Inspectables

    /**
     Defines the color of the shadow behind the view (defaults to nil).
     */

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

    /**
     Defines the radius of the shadow behind the view.
     */

    @IBInspectable public var shadowRadius: CGFloat {
        set(newValue) {
            self.layer.shadowRadius = newValue
        } get {
            return self.layer.shadowRadius
        }
    }

    /**
     Defines the opacity of the shadow behind the view.
     */

    @IBInspectable public var shadowOpacity: Float {
        set(newValue) {
            self.layer.shadowOpacity = newValue
        } get {
            return self.layer.shadowOpacity
        }
    }

    /**
     Defines the offset of the shadow behind the view.
     */

    @IBInspectable public var shadowOffset: CGSize {
        set(newValue) {
            self.layer.shadowOffset = newValue
        } get {
            return self.layer.shadowOffset
        }
    }

}

然后，您将能够在故事板上找到每个UIView（或从UIView继承的类）的后一个参数。

但是，如果您正在以编程方式进行工作，则必须尝试使用shadowOffset属性，直到获得所需的视觉效果为止。

将阴影添加到选定的Edges UIView

2 个答案: