使用 Swift 3在 UIView 上添加 Shadow

之前的 Swift 3我在我的 UIView 中添加了这样的阴影:

//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

但是上面的代码不能在快速3中工作，取而代之的是阴影，我的整个视图的颜色变成了难看的灰色

有人知道怎样在迅捷3中加入阴影吗？

183050 次浏览
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最佳答案

代码 SNIPPET: 

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 : 如果不将 任何参数传递给该函数，则缺省情况下 scale 参数为 true。通过在参数的类型之后为参数赋值，可以为函数中的任何参数定义默认值。如果定义了默认值，则可以在调用函数时省略该参数。

输出1:

shadowView.dropShadow()

enter image description here

输出2:

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

enter image description here

layer.shouldRasterize = true将使阴影静态化，并使 UIView的初始状态产生阴影。所以我建议不要在动态布局中使用 layer.shouldRasterize = true，比如在 UITableViewCell中使用 view。

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使用 UIView 扩展的阴影 Swift 4

我想添加一个选定的答案行！ 当我们光栅化图层时，它需要设置为2.0来显示视网膜。否则标签上的文字或图像视图将是模糊的。所以我们还需要添加 rasterizationScale。

  extension UIView {


func dropShadow() {
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: self.bounds).cgPath
layer.shouldRasterize = true
layer.rasterizationScale = UIScreen.main.scale
}
}
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虽然 接受的答案是伟大的，它的工作，因为它应该，我已经修改了它分裂 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
}
}
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非常简单，代码行很少:

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)

看起来像: enter image description here

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loginView.layer.shadowOpacity = 1.0
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这对我有用(Swift 3和4)

yourView.layer.shadowColor = UIColor.gray.cgColor
yourView.layer.shadowOpacity = 0.3
yourView.layer.shadowOffset = CGSize.zero
yourView.layer.shadowRadius = 6
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Swift 4

toolbar.layer.shadowColor = UIColor.hex(hexColor: "#000000", withAlpha: 1.0).cgColor
toolbar.layer.shadowOffset = CGSize.zero
toolbar.layer.shadowRadius = 1
toolbar.layer.shadowOpacity = 1
toolbar.layer.shouldRasterize = true
toolbar.layer.masksToBounds = false
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如果希望将其用作视图的 IBChectable 属性，可以添加此扩展

import UIKit


extension UIView {


private static var _addShadow:Bool = false


@IBInspectable var addShadow:Bool {
get {
return UIView._addShadow
}
set(newValue) {
if(newValue == true){
layer.masksToBounds = false
layer.shadowColor = UIColor.black.cgColor
layer.shadowOpacity = 0.075
layer.shadowOffset = CGSize(width: 0, height: -3)
layer.shadowRadius = 1


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


}
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在视图上应用阴影

func applyShadowOnView(_ view:UIView) {


view.layer.cornerRadius = 8
view.layer.shadowColor = UIColor.darkGray.cgColor
view.layer.shadowOpacity = 1
view.layer.shadowOffset = CGSize.zero
view.layer.shadowRadius = 5


}
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如果你需要圆形的阴影，可以用迅捷4.2

extension UIView {


func dropShadow() {


var shadowLayer: CAShapeLayer!
let cornerRadius: CGFloat = 16.0
let fillColor: UIColor = .white


if shadowLayer == nil {
shadowLayer = CAShapeLayer()


shadowLayer.path = UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).cgPath
shadowLayer.fillColor = fillColor.cgColor


shadowLayer.shadowColor = UIColor.black.cgColor
shadowLayer.shadowPath = shadowLayer.path
shadowLayer.shadowOffset = CGSize(width: -2.0, height: 2.0)
shadowLayer.shadowOpacity = 0.8
shadowLayer.shadowRadius = 2


layer.insertSublayer(shadowLayer, at: 0)
}
}
}

带阴影的 Swift 4圆形 UIView

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试试这个

func applyShadowOnView(_ view: UIView) {
view.layer.cornerRadius = 8
view.layer.shadowColor = UIColor.darkGray.cgColor
view.layer.shadowOpacity = 1
view.layer.shadowOffset = .zero
view.layer.shadowRadius = 5
}
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我们也可以通过以下方式应用阴影

    cell.view1.layer.masksToBounds = false
cell.view1.layer.shadowColor = UIColor.lightGray.cgColor
cell.view1.backgroundColor = UIColor.white
cell.view1.layer.shadowOffset = CGSize(width: 1.0, height: 1.0)
cell.view1.layer.shadowOpacity = 0.5

结果是: http://prntscr.com/nhhv2s

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请试试这个，对我很有效。

extension UIView {


func dropShadow() {
    

layer.shadowColor = UIColor.black.cgColor
layer.shadowOffset = CGSize(width: 2, height: 3)
layer.masksToBounds = false
    

layer.shadowOpacity = 0.3
layer.shadowRadius = 3
//layer.shadowPath = UIBezierPath(rect: bounds).cgPath
layer.rasterizationScale = UIScreen.main.scale
layer.shouldRasterize = true
}
}
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Swift 5 只需调用这个函数并传递视图

public func setViewSettingWithBgShade(view: UIView)
{
view.layer.cornerRadius = 8
view.layer.borderWidth = 1
view.layer.borderColor = UIColor.red.cgColor
    

//MARK:- Shade a view
view.layer.shadowOpacity = 0.5
view.layer.shadowOffset = CGSize(width: 1.0, height: 1.0)
view.layer.shadowRadius = 3.0
view.layer.shadowColor = UIColor.black.cgColor
view.layer.masksToBounds = false
}
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非常容易使用 UIView 扩展，可直接从故事板编辑

@IBDesignable extension UIView {
@IBInspectable var shadowColor: UIColor?{
set {
guard let uiColor = newValue else { return }
layer.shadowColor = uiColor.cgColor
}
get{
guard let color = layer.shadowColor else { return nil }
return UIColor(cgColor: color)
}
}


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


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


@IBInspectable var shadowRadius: CGFloat{
set {
layer.shadowRadius = newValue
}
get{
return layer.shadowRadius
}
}
}
小开 
    func shadow(Vw : UIView)
{
Vw.layer.masksToBounds = false
Vw.layer.shadowColor =  colorLiteral(red: 0.5058823529, green: 0.5333333333, blue: 0.6117647059, alpha: 1)
Vw.layer.shadowOffset = CGSize(width: 0, height: 1)
Vw.layer.shadowRadius = 5.0
Vw.layer.shadowOpacity = 15.0
Vw.layer.cornerRadius = 5.0
}
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经过大量的时间，我只是找到了解决方案，只是添加这个简单的行。

颜色 = 。白色

希望这个能帮到你！

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我建议您在库下面使用，因为它允许您在一个文件中设置默认值，并且您可以在项目的任何地方使用它，而不需要进行任何更改。 Https://github.com/shahbaz89khan/shadowview

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对于迅速的5个用户可以这样做。

extension UIView {
func addShadow() {
self.layer.shadowColor = UIColor.gray.cgColor
self.layer.shadowOffset = CGSize(width: 1, height: 1)
self.layer.shadowOpacity = 1
}
}

enter image description here

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IOS 影子

[高级示例]

您可以使用 layer设置阴影

view1.layer.shadowColor = UIColor.magenta.cgColor


view1.layer.shadowOffset = CGSize(width: 0, height: 0)
view1.layer.shadowOpacity = 1
view1.layer.shadowRadius = 0

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