我抬起头但是我无法找到如何为UIView添加内部阴影,只为Swift添加顶部(从上到下)。在Swift中添加内圈的最佳方法是什么?
编辑:我发现了一些问题&然而,他们要么是obj-c,要么看起来如此复杂。如果有任何
,我只是想找一个更加Swifty的方式我想要实现的目标:
答案 0 :(得分:21)
这是我提出的一个纯粹的Swift版本:
public class EdgeShadowLayer: CAGradientLayer {
public enum Edge {
case Top
case Left
case Bottom
case Right
}
public init(forView view: UIView,
edge: Edge = Edge.Top,
shadowRadius radius: CGFloat = 20.0,
toColor: UIColor = UIColor.white,
fromColor: UIColor = UIColor.black) {
super.init()
self.colors = [fromColor.cgColor, toColor.cgColor]
self.shadowRadius = radius
let viewFrame = view.frame
switch edge {
case .Top:
startPoint = CGPoint(x: 0.5, y: 0.0)
endPoint = CGPoint(x: 0.5, y: 1.0)
self.frame = CGRect(x: 0.0, y: 0.0, width: viewFrame.width, height: shadowRadius)
case .Bottom:
startPoint = CGPoint(x: 0.5, y: 1.0)
endPoint = CGPoint(x: 0.5, y: 0.0)
self.frame = CGRect(x: 0.0, y: viewFrame.height - shadowRadius, width: viewFrame.width, height: shadowRadius)
case .Left:
startPoint = CGPoint(x: 0.0, y: 0.5)
endPoint = CGPoint(x: 1.0, y: 0.5)
self.frame = CGRect(x: 0.0, y: 0.0, width: shadowRadius, height: viewFrame.height)
case .Right:
startPoint = CGPoint(x: 1.0, y: 0.5)
endPoint = CGPoint(x: 0.0, y: 0.5)
self.frame = CGRect(x: viewFrame.width - shadowRadius, y: 0.0, width: shadowRadius, height: viewFrame.height)
}
}
required public init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
要使用它,
let topShadow = EdgeShadowLayer(forView: targetView, edge: .Top)
targetView.layer.addSublayer(topShadow)
请注意,它默认为黑色至白色渐变,深度为20点。
可以在https://github.com/jrtibbetts/Tenebrae找到包含示例UIViewController
的完整代码,该示例可让您在视图的所有四个角上切换阴影。我还非常详细地记录了EdgeShadowLayer
。
答案 1 :(得分:14)
我使用Objective-C将实现内部阴影用于UIView。我尝试将代码翻译成swift。请原谅我糟糕的快速语法
您可以在UIView.didMoveToSuperview
中调用以下功能func drawShadow() {
if nil == self.shadowLayer {
let size = self.frame.size
self.clipsToBounds = true
let layer: CALayer = CALayer()
layer.backgroundColor = UIColor.lightGrayColor().CGColor
layer.position = CGPointMake(size.width / 2, -size.height / 2 + 0.5)
layer.bounds = CGRectMake(0, 0, size.width, size.height)
layer.shadowColor = UIColor.darkGrayColor().CGColor
layer.shadowOffset = CGSizeMake(0.5, 0.5)
layer.shadowOpacity = 0.8
layer.shadowRadius = 5.0
self.shadowLayer = layer
self.layer.addSublayer(layer)
}
}
答案 2 :(得分:2)
我在Swift 3上重写了@NRitH解决方案,也稍微重构了它:
final class SideShadowLayer: CAGradientLayer {
enum Side {
case top,
bottom,
left,
right
}
init(frame: CGRect, side: Side, shadowWidth: CGFloat,
fromColor: UIColor = .black,
toColor: UIColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0),
opacity: Float = 0.5) {
super.init()
colors = [fromColor.cgColor, toColor.cgColor]
self.opacity = opacity
switch side {
case .bottom:
startPoint = CGPoint(x: 0.5, y: 1.0)
endPoint = CGPoint(x: 0.5, y: 0.0)
self.frame = CGRect(x: 0, y: frame.height - shadowWidth, width: frame.width, height: shadowWidth)
case .top:
startPoint = CGPoint(x: 0.5, y: 0.0)
endPoint = CGPoint(x: 0.5, y: 1.0)
self.frame = CGRect(x: 0, y: 0, width: frame.width, height: shadowWidth)
case .left:
startPoint = CGPoint(x: 0.0, y: 0.5)
endPoint = CGPoint(x: 1.0, y: 0.5)
self.frame = CGRect(x: 0, y: 0, width: shadowWidth, height: frame.height)
case .right:
startPoint = CGPoint(x: 1.0, y: 0.5)
endPoint = CGPoint(x: 0.0, y: 0.5)
self.frame = CGRect(x: frame.width - shadowWidth, y: 0, width: shadowWidth, height: frame.height)
}
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
答案 3 :(得分:2)
我更新了@NRitH的答案,并对其进行了扩展,并对其进行了修改,以便您可以一次操作多个边缘
使用
myview.addShadow(to: [.top,.bottom], radius: 15.0)
extension UIView{
func addShadow(to edges:[UIRectEdge], radius:CGFloat){
let toColor = UIColor(colorLiteralRed: 235.0/255.0, green: 235.0/255.0, blue: 235.0/255.0, alpha: 1.0)
let fromColor = UIColor(colorLiteralRed: 188.0/255.0, green: 188.0/255.0, blue: 188.0/255.0, alpha: 1.0)
// Set up its frame.
let viewFrame = self.frame
for edge in edges{
let gradientlayer = CAGradientLayer()
gradientlayer.colors = [fromColor.cgColor,toColor.cgColor]
gradientlayer.shadowRadius = radius
switch edge {
case UIRectEdge.top:
gradientlayer.startPoint = CGPoint(x: 0.5, y: 0.0)
gradientlayer.endPoint = CGPoint(x: 0.5, y: 1.0)
gradientlayer.frame = CGRect(x: 0.0, y: 0.0, width: viewFrame.width, height: gradientlayer.shadowRadius)
case UIRectEdge.bottom:
gradientlayer.startPoint = CGPoint(x: 0.5, y: 1.0)
gradientlayer.endPoint = CGPoint(x: 0.5, y: 0.0)
gradientlayer.frame = CGRect(x: 0.0, y: viewFrame.height - gradientlayer.shadowRadius, width: viewFrame.width, height: gradientlayer.shadowRadius)
case UIRectEdge.left:
gradientlayer.startPoint = CGPoint(x: 0.0, y: 0.5)
gradientlayer.endPoint = CGPoint(x: 1.0, y: 0.5)
gradientlayer.frame = CGRect(x: 0.0, y: 0.0, width: gradientlayer.shadowRadius, height: viewFrame.height)
case UIRectEdge.right:
gradientlayer.startPoint = CGPoint(x: 1.0, y: 0.5)
gradientlayer.endPoint = CGPoint(x: 0.0, y: 0.5)
gradientlayer.frame = CGRect(x: viewFrame.width - gradientlayer.shadowRadius, y: 0.0, width: gradientlayer.shadowRadius, height: viewFrame.height)
default:
break
}
self.layer.addSublayer(gradientlayer)
}
}
func removeAllSublayers(){
if let sublayers = self.layer.sublayers, !sublayers.isEmpty{
for sublayer in sublayers{
sublayer.removeFromSuperlayer()
}
}
}
}
答案 4 :(得分:1)
我使用@作为清晰的toColor
调整了@ anoop4real所做的修改,并使界面与CALayer中的阴影设置(包括默认设置)更加一致,除了不透明性(将不透明性设置为0.0)默认。我使用默认值0.6,因为它看起来是最自然的。
extension UIView {
func addShadow(to edges: [UIRectEdge], radius: CGFloat = 3.0, opacity: Float = 0.6, color: CGColor = UIColor.black.cgColor) {
let fromColor = color
let toColor = UIColor.clear.cgColor
let viewFrame = self.frame
for edge in edges {
let gradientLayer = CAGradientLayer()
gradientLayer.colors = [fromColor, toColor]
gradientLayer.opacity = opacity
switch edge {
case .top:
gradientLayer.startPoint = CGPoint(x: 0.5, y: 0.0)
gradientLayer.endPoint = CGPoint(x: 0.5, y: 1.0)
gradientLayer.frame = CGRect(x: 0.0, y: 0.0, width: viewFrame.width, height: radius)
case .bottom:
gradientLayer.startPoint = CGPoint(x: 0.5, y: 1.0)
gradientLayer.endPoint = CGPoint(x: 0.5, y: 0.0)
gradientLayer.frame = CGRect(x: 0.0, y: viewFrame.height - radius, width: viewFrame.width, height: radius)
case .left:
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.5)
gradientLayer.frame = CGRect(x: 0.0, y: 0.0, width: radius, height: viewFrame.height)
case .right:
gradientLayer.startPoint = CGPoint(x: 1.0, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 0.0, y: 0.5)
gradientLayer.frame = CGRect(x: viewFrame.width - radius, y: 0.0, width: radius, height: viewFrame.height)
default:
break
}
self.layer.addSublayer(gradientLayer)
}
}
func removeAllShadows() {
if let sublayers = self.layer.sublayers, !sublayers.isEmpty {
for sublayer in sublayers {
sublayer.removeFromSuperlayer()
}
}
}
}
顶视图是默认设置,底视图使用半径5.0来更清晰地显示。
view1.addShadow([.top, .bottom, .left, .right])
view2.addShadow([.top, .bottom, .left, .right], radius: 5.0)
view2.backgroundColor = .orange
答案 5 :(得分:0)
这就是我在视图中添加内部阴影的方式。
func addInerShadowLayer()
{
clipsToBounds = true
let shapeLayer = CAShapeLayer()
let path = UIBezierPath(roundedRect: CGRect(x: -10, y: -self.frame.height/2, width: self.frame.width + 20, height: self.frame.height*2), cornerRadius: 0)
let buttonPath = UIBezierPath(roundedRect: CGRect(x: -1, y: -1, width: self.frame.width+2, height: self.frame.height+2), cornerRadius: self.frame.height/2)
path.append(buttonPath.reversing())
shapeLayer.path = path.cgPath
self.layer.addSublayer(shapeLayer)
shapeLayer.shadowOpacity = 0.1
shapeLayer.shadowColor = UIColor.red.cgColor
shapeLayer.shadowOffset = CGSize(width: 0, height: 4)
shapeLayer.shadowRadius = 3
}
答案 6 :(得分:0)
如果您不介意使用 clipsToBounds = true
,您可以在视图边缘附近创建一个新的 CALayer
偏移量,并将阴影添加到该视图中。这就是 J.Hunter 的回答。
J.Hunter 的代码添加了顶部阴影,这里我将其更新为 Swift 5 并添加到底部。
斯威夫特 5:
override func draw(_ rect: CGRect) {
// Create Inner Shadow. Not sure about efficiency of this.
// You may want to create a shadowLayer property
// and only run this code if it hasn't been created yet.
let size = rect.size
clipsToBounds = true // Don't want to see your fake view layer
let innerShadowLayer: CALayer = CALayer()
// Need to set a backgroundColor or it doesn't work
innerShadowLayer.backgroundColor = UIColor.black.cgColor
// Position your shadow layer (anchor point is in the center)
// on the edge of where your shadow needs to be.
// In my case this moves the shadow layer to the
// bottom edge of my view
innerShadowLayer.position = CGPoint(x: size.width / 2, y: size.height + (size.height / 2))
// This could be smaller I think, just copying J.Hunter's code...
innerShadowLayer.bounds = CGRect(x: 0, y: 0, width: size.width, height: size.height)
// Normal shadow layer properties you'd use for an outer shadow
innerShadowLayer.shadowColor = UIColor.black.cgColor
innerShadowLayer.shadowOffset = CGSize(width: 0, height: 0)
innerShadowLayer.shadowOpacity = 0.3
innerShadowLayer.shadowRadius = 3
layer.addSublayer(innerShadowLayer)
}