我在草图中设计了UI元素,其中一个具有模糊1和传播0的阴影。我查看了视图图层属性的文档,图层没有任何名为spread或blur的东西,或者任何等效的东西(唯一的控件是only shadowOpacity)如何控制模糊和传播之类的东西?
编辑:
以下是我在Sketch中的设置: 这就是我希望我的阴影看起来像:
我的代码如下:
func setupLayer(){
view.layer.cornerRadius = 2
view.layer.shadowColor = Colors.Shadow.CGColor
view.layer.shadowOffset = CGSize(width: 0, height: 1)
view.layer.shadowOpacity = 0.9
view.layer.shadowRadius = 5
}
以下是如何将所有6个Sketch阴影属性应用于UIView的图层,具有接近完美的精度:
extension CALayer {
func applySketchShadow(
color: UIColor = .black,
alpha: Float = 0.5,
x: CGFloat = 0,
y: CGFloat = 2,
blur: CGFloat = 4,
spread: CGFloat = 0)
{
shadowColor = color.cgColor
shadowOpacity = alpha
shadowOffset = CGSize(width: x, height: y)
shadowRadius = blur / 2.0
if spread == 0 {
shadowPath = nil
} else {
let dx = -spread
let rect = bounds.insetBy(dx: dx, dy: dx)
shadowPath = UIBezierPath(rect: rect).cgPath
}
}
}
假设我们想要代表以下内容:
您可以通过以下方式轻松完成
myView.layer.applySketchShadow(
color: .black,
alpha: 0.5,
x: 0,
y: 0,
blur: 4,
spread: 0)
或者更简洁:
myView.layer.applySketchShadow(y: 0)
例:
左:iPhone 8 UIView截图;右:草图矩形。
注意:
spread
时,它基于CALayer的bounds
硬编码路径。如果图层的边界发生变化,您需要再次调用applySketchShadow()
方法。你可以尝试这个......你可以玩这些值。 shadowRadius
决定了模糊的数量。 shadowOffset
决定阴影的去向。
Swift 2.0
let radius: CGFloat = demoView.frame.width / 2.0 //change it to .height if you need spread for height
let shadowPath = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 2.1 * radius, height: demoView.frame.height))
//Change 2.1 to amount of spread you need and for height replace the code for height
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.blackColor().CGColor
demoView.layer.shadowOffset = CGSize(width: 0.5, height: 0.4) //Here you control x and y
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
demoView.layer.masksToBounds = false
demoView.layer.shadowPath = shadowPath.CGPath
Swift 3.0
let radius: CGFloat = demoView.frame.width / 2.0 //change it to .height if you need spread for height
let shadowPath = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 2.1 * radius, height: demoView.frame.height))
//Change 2.1 to amount of spread you need and for height replace the code for height
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.black.cgColor
demoView.layer.shadowOffset = CGSize(width: 0.5, height: 0.4) //Here you control x and y
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
demoView.layer.masksToBounds = false
demoView.layer.shadowPath = shadowPath.cgPath
传播的例子
创建基本阴影
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.blackColor().CGColor
demoView.layer.shadowOffset = CGSizeMake(0.5, 4.0); //Here your control your spread
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
Swift 2.0中的基本阴影示例
在Swift 4中使用IBDesignable和IBInspectable绘制阴影
侧面的草图和XCODE
码
@IBDesignable class ShadowView: UIView {
@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
}
}
}
@IBInspectable var shadowOpacity: Float {
get {
return layer.shadowOpacity
}
set {
layer.shadowOpacity = newValue
}
}
@IBInspectable var shadowOffset: CGPoint {
get {
return CGPoint(x: layer.shadowOffset.width, y:layer.shadowOffset.height)
}
set {
layer.shadowOffset = CGSize(width: newValue.x, height: newValue.y)
}
}
@IBInspectable var shadowBlur: CGFloat {
get {
return layer.shadowRadius
}
set {
layer.shadowRadius = newValue / 2.0
}
}
@IBInspectable var shadowSpread: CGFloat = 0 {
didSet {
if shadowSpread == 0 {
layer.shadowPath = nil
} else {
let dx = -shadowSpread
let rect = bounds.insetBy(dx: dx, dy: dx)
layer.shadowPath = UIBezierPath(rect: rect).cgPath
}
}
}
}
OUTPUT
如何使用它
这段代码对我很有用:
yourView.layer.shadowOpacity = 0.2 // opacity, 20%
yourView.layer.shadowColor = UIColor.black.cgColor
yourView.layer.shadowRadius = 2 // HALF of blur
yourView.layer.shadowOffset = CGSize(width: 0, height: 2) // Spread x, y
yourView.layer.masksToBounds = false
对于那些试图将阴影应用于预定义路径的人(例如,对于圆形视图),这就是我最终得到的结果:
extension CALayer {
func applyShadow(color: UIColor = .black,
alpha: Float = 0.5,
x: CGFloat = 0,
y: CGFloat = 2,
blur: CGFloat = 4,
spread: CGFloat = 0,
path: UIBezierPath? = nil) {
shadowColor = color.cgColor
shadowOpacity = alpha
shadowRadius = blur / 2
if let path = path {
if spread == 0 {
shadowOffset = CGSize(width: x, height: y)
} else {
let scaleX = (path.bounds.width + (spread * 2)) / path.bounds.width
let scaleY = (path.bounds.height + (spread * 2)) / path.bounds.height
path.apply(CGAffineTransform(translationX: x + -spread, y: y + -spread).scaledBy(x: scaleX, y: scaleY))
shadowPath = path.cgPath
}
} else {
shadowOffset = CGSize(width: x, height: y)
if spread == 0 {
shadowPath = nil
} else {
let dx = -spread
let rect = bounds.insetBy(dx: dx, dy: dx)
shadowPath = UIBezierPath(rect: rect).cgPath
}
}
shouldRasterize = true
rasterizationScale = UIScreen.main.scale
}
}
我稍后会发布一些例子,但这对我来说是圆形视图。
基于这篇文章我的解决方案回复:( Swift 3)
let shadowPath = UIBezierPath(rect: CGRect(x: -1,
y: -2,
width: target.frame.width + 2,
height: target.frame.height + 2))
target.layer.shadowColor = UIColor(hexString: shadowColor).cgColor
target.layer.shadowOffset = CGSize(width: CGFloat(shadowOffsetX), height: CGFloat(shadowOffsetY))
target.layer.masksToBounds = false
target.layer.shadowOpacity = Float(shadowOpacity)
target.layer.shadowPath = shadowPath.cgPath
这可能是历史上的一点点,但也许有些人有同样的问题。我使用了来自已接受答案的代码示例。然而效果是完全不同的: - y值必须是草图中相同值的一半左右 - 我试图在导航栏上应用阴影,效果非常不同 - 使用草图所具有的相同值时几乎看不到。
所以似乎该方法完全没有反映草图参数。任何提示?