如何在Swift 3中为UIView提供底影？

Question

我想要

我的代码

let shadowPath = UIBezierPath(rect: shadowView.bounds).cgPath
shadowView.layer.shadowColor = UIColor.grey.cgColor
shadowView.layer.shadowOffset = CGSize(width: 0, height: 1)
shadowView.layer.shadowOpacity = 0.5
shadowView.layer.masksToBounds = false
shadowView.layer.shadowPath = shadowPath
shadowView.layer.shadowRadius = 5

我想在我的UIVIew中实现完全相同的阴影。当我使用上面的代码运行我的应用程序时，它分布在4个方面。注意：阴影在两边都很薄，在中心处是粗体。

Answer 1

尝试创建自定义路径：

let shadowPath = UIBezierPath()
shadowPath.move(to: CGPoint(x: someView.bounds.origin.x, y: someView.frame.size.height))
shadowPath.addLine(to: CGPoint(x: someView.bounds.width / 2, y: someView.bounds.height + 7.0))
shadowPath.addLine(to: CGPoint(x: someView.bounds.width, y: someView.bounds.height))
shadowPath.close()

shadowView.layer.shadowColor = UIColor.darkGray.cgColor
shadowView.layer.shadowOpacity = 1
shadowView.layer.masksToBounds = false
shadowView.layer.shadowPath = shadowPath.cgPath
shadowView.layer.shadowRadius = 5

这会产生类似的结果，尝试自定义积分位置和其他值以满足您的需求。

Answer 2

稍微改变@jonaszmclaren给出一个矩形阴影：

func makeBottomShadow(forView view: UIView, shadowHeight: CGFloat = 5) {
    let shadowPath = UIBezierPath()
    shadowPath.move(to: CGPoint(x: 0, y: view.bounds.height))
    shadowPath.addLine(to: CGPoint(x: view.bounds.width, y: view.bounds.height))
    shadowPath.addLine(to: CGPoint(x: view.bounds.width, y: view.bounds.height + shadowHeight))
    shadowPath.addLine(to: CGPoint(x: 0, y: view.bounds.height + shadowHeight))
    shadowPath.close()

    view.layer.shadowColor = UIColor.darkGray.cgColor
    view.layer.shadowOpacity = 0.5
    view.layer.masksToBounds = false
    view.layer.shadowPath = shadowPath.cgPath
    view.layer.shadowRadius = 2
}

Answer 3

试一试

<强> IBOutlet中

@IBOutlet weak var vwShadow: UIView!

在ViewdidLoad

中

vwShadow.layer.shadowColor = UIColor.gray.cgColor
vwShadow.layer.masksToBounds = false
vwShadow.layer.shadowOffset = CGSize(width: 0.0 , height: 5.0)
vwShadow.layer.shadowOpacity = 1.0
vwShadow.layer.shadowRadius = 1.0