上的UIView使用SWIFT 3

Question

之前迅速3我被添加陰影添加陰影在我UIView是這樣的：

//toolbar is an UIToolbar (UIView) 
toolbar.layer.masksToBounds = false 
toolbar.layer.shadowOffset = CGSize(width: -1, height: 1) 
toolbar.layer.shadowRadius = 1 
toolbar.layer.shadowOpacity = 0.5 

，但上面的代碼是不是在迅速3個工作，而不是影子我的整個景觀的色彩被打開以醜陋的灰色

的人都知道，我們如何能在迅速增加3陰影？

Answer 1

代碼片段：

extension UIView { 

    // OUTPUT 1 
    func dropShadow(scale: Bool = true) { 
    layer.masksToBounds = false 
    layer.shadowColor = UIColor.black.cgColor 
    layer.shadowOpacity = 0.5 
    layer.shadowOffset = CGSize(width: -1, height: 1) 
    layer.shadowRadius = 1 

    layer.shadowPath = UIBezierPath(rect: bounds).cgPath 
    layer.shouldRasterize = true 
    layer.rasterizationScale = scale ? UIScreen.main.scale : 1 
    } 

    // OUTPUT 2 
    func dropShadow(color: UIColor, opacity: Float = 0.5, offSet: CGSize, radius: CGFloat = 1, scale: Bool = true) { 
    layer.masksToBounds = false 
    layer.shadowColor = color.cgColor 
    layer.shadowOpacity = opacity 
    layer.shadowOffset = offSet 
    layer.shadowRadius = radius 

    layer.shadowPath = UIBezierPath(rect: self.bounds).cgPath 
    layer.shouldRasterize = true 
    layer.rasterizationScale = scale ? UIScreen.main.scale : 1 
    } 
} 

注意：如果你沒有通過任何參數該功能，那麼規模參數將默認爲true。您可以通過在該參數的類型之後爲該參數分配一個值來爲函數中的任何參數定義默認值。如果定義了默認值，則可以在調用該函數時省略該參數。

OUTPUT 1：

shadowView.dropShadow() 

OUTPUT 2：

shadowView.dropShadow(color: .red, opacity: 1, offSet: CGSize(width: -1, height: 1), radius: 3, scale: true) 

Answer 2

我想補充一個更符合選擇的答案！ 當我們光柵化層，它需要被設定爲2.0視網膜顯示器。否則，該視圖上的標籤文本或圖像將變得模糊。所以我們還需要添加rasterizationScale。

extension UIView { 

    func dropShadow() { 

     self.layer.masksToBounds = false 
     self.layer.shadowColor = UIColor.black.cgColor 
     self.layer.shadowOpacity = 0.5 
     self.layer.shadowOffset = CGSize(width: -1, height: 1) 
     self.layer.shadowRadius = 1 

     self.layer.shadowPath = UIBezierPath(rect: self.bounds).cgPath 
     self.layer.shouldRasterize = true 

     self.layer.rasterizationScale = UIScreen.main.scale 

    } 
} 

Answer 3

雖然accepted answer是偉大的，它的作品，因爲它應該，我已經修改了它分裂offSet: CGSize到offsetX: CGFloat和offsetY: CGFloat。

extension UIView { 
    func dropShadow(offsetX: CGFloat, offsetY: CGFloat, color: UIColor, opacity: Float, radius: CGFloat, scale: Bool = true) { 
    layer.masksToBounds = false 
    layer.shadowOffset = CGSize(width: offsetX, height: offsetY) 
    layer.shadowColor = color.cgColor 
    layer.shadowOpacity = opacity 
    layer.shadowRadius = radius 
    layer.shadowPath = UIBezierPath(rect: self.bounds).cgPath 
    layer.shouldRasterize = true 
    layer.rasterizationScale = scale ? UIScreen.main.scale : 1 
    } 
} 

Answer 4

非常簡單，幾行代碼：

let viewShadow = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200)) 
viewShadow.center = self.view.center 
viewShadow.backgroundColor = UIColor.yellow 
viewShadow.layer.shadowColor = UIColor.red.cgColor 
viewShadow.layer.shadowOpacity = 1 
viewShadow.layer.shadowOffset = CGSize.zero 
viewShadow.layer.shadowRadius = 5 
self.view.addSubview(viewShadow) 

樣子：