我试图应用渐变作为一个视图(故事板的主视图)的背景色。代码运行，但没有任何变化。我使用xCode Beta 2和Swift。
代码如下:
class Colors {
let colorTop = UIColor(red: 192.0/255.0, green: 38.0/255.0, blue: 42.0/255.0, alpha: 1.0)
let colorBottom = UIColor(red: 35.0/255.0, green: 2.0/255.0, blue: 2.0/255.0, alpha: 1.0)
let gl: CAGradientLayer
init() {
gl = CAGradientLayer()
gl.colors = [ colorTop, colorBottom]
gl.locations = [ 0.0, 1.0]
}
}
然后在视图控制器中:
let colors = Colors()
func refresh() {
view.backgroundColor = UIColor.clearColor()
var backgroundLayer = colors.gl
backgroundLayer.frame = view.frame
view.layer.insertSublayer(backgroundLayer, atIndex: 0)
}
}
}
我有这些扩展:
@IBDesignable class GradientView: UIView {
@IBInspectable var firstColor: UIColor = UIColor.red
@IBInspectable var secondColor: UIColor = UIColor.green
@IBInspectable var vertical: Bool = true
lazy var gradientLayer: CAGradientLayer = {
let layer = CAGradientLayer()
layer.colors = [firstColor.cgColor, secondColor.cgColor]
layer.startPoint = CGPoint.zero
return layer
}()
//MARK: -
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
applyGradient()
}
override init(frame: CGRect) {
super.init(frame: frame)
applyGradient()
}
override func prepareForInterfaceBuilder() {
super.prepareForInterfaceBuilder()
applyGradient()
}
override func layoutSubviews() {
super.layoutSubviews()
updateGradientFrame()
}
//MARK: -
func applyGradient() {
updateGradientDirection()
layer.sublayers = [gradientLayer]
}
func updateGradientFrame() {
gradientLayer.frame = bounds
}
func updateGradientDirection() {
gradientLayer.endPoint = vertical ? CGPoint(x: 0, y: 1) : CGPoint(x: 1, y: 0)
}
}
@IBDesignable class ThreeColorsGradientView: UIView {
@IBInspectable var firstColor: UIColor = UIColor.red
@IBInspectable var secondColor: UIColor = UIColor.green
@IBInspectable var thirdColor: UIColor = UIColor.blue
@IBInspectable var vertical: Bool = true {
didSet {
updateGradientDirection()
}
}
lazy var gradientLayer: CAGradientLayer = {
let layer = CAGradientLayer()
layer.colors = [firstColor.cgColor, secondColor.cgColor, thirdColor.cgColor]
layer.startPoint = CGPoint.zero
return layer
}()
//MARK: -
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
applyGradient()
}
override init(frame: CGRect) {
super.init(frame: frame)
applyGradient()
}
override func prepareForInterfaceBuilder() {
super.prepareForInterfaceBuilder()
applyGradient()
}
override func layoutSubviews() {
super.layoutSubviews()
updateGradientFrame()
}
//MARK: -
func applyGradient() {
updateGradientDirection()
layer.sublayers = [gradientLayer]
}
func updateGradientFrame() {
gradientLayer.frame = bounds
}
func updateGradientDirection() {
gradientLayer.endPoint = vertical ? CGPoint(x: 0, y: 1) : CGPoint(x: 1, y: 0)
}
}
@IBDesignable class RadialGradientView: UIView {
@IBInspectable var outsideColor: UIColor = UIColor.red
@IBInspectable var insideColor: UIColor = UIColor.green
override func awakeFromNib() {
super.awakeFromNib()
applyGradient()
}
func applyGradient() {
let colors = [insideColor.cgColor, outsideColor.cgColor] as CFArray
let endRadius = sqrt(pow(frame.width/2, 2) + pow(frame.height/2, 2))
let center = CGPoint(x: bounds.size.width / 2, y: bounds.size.height / 2)
let gradient = CGGradient(colorsSpace: nil, colors: colors, locations: nil)
let context = UIGraphicsGetCurrentContext()
context?.drawRadialGradient(gradient!, startCenter: center, startRadius: 0.0, endCenter: center, endRadius: endRadius, options: CGGradientDrawingOptions.drawsBeforeStartLocation)
}
override func draw(_ rect: CGRect) {
super.draw(rect)
#if TARGET_INTERFACE_BUILDER
applyGradient()
#endif
}
}
用法:
我把罗希特·西索迪亚和米高梅的答案混在了一起
// MARK: - Gradient
public enum CAGradientPoint {
case topLeft
case centerLeft
case bottomLeft
case topCenter
case center
case bottomCenter
case topRight
case centerRight
case bottomRight
var point: CGPoint {
switch self {
case .topLeft:
return CGPoint(x: 0, y: 0)
case .centerLeft:
return CGPoint(x: 0, y: 0.5)
case .bottomLeft:
return CGPoint(x: 0, y: 1.0)
case .topCenter:
return CGPoint(x: 0.5, y: 0)
case .center:
return CGPoint(x: 0.5, y: 0.5)
case .bottomCenter:
return CGPoint(x: 0.5, y: 1.0)
case .topRight:
return CGPoint(x: 1.0, y: 0.0)
case .centerRight:
return CGPoint(x: 1.0, y: 0.5)
case .bottomRight:
return CGPoint(x: 1.0, y: 1.0)
}
}
}
extension CAGradientLayer {
convenience init(start: CAGradientPoint, end: CAGradientPoint, colors: [CGColor], type: CAGradientLayerType) {
self.init()
self.frame.origin = CGPoint.zero
self.startPoint = start.point
self.endPoint = end.point
self.colors = colors
self.locations = (0..<colors.count).map(NSNumber.init)
self.type = type
}
}
extension UIView {
func layerGradient(startPoint:CAGradientPoint, endPoint:CAGradientPoint ,colorArray:[CGColor], type:CAGradientLayerType ) {
let gradient = CAGradientLayer(start: .topLeft, end: .topRight, colors: colorArray, type: type)
gradient.frame.size = self.frame.size
self.layer.insertSublayer(gradient, at: 0)
}
}
To Use写:-
btnUrdu.layer.cornerRadius = 25
btnUrdu.layer.masksToBounds = true
btnUrdu.layerGradient(startPoint: .centerRight, endPoint: .centerLeft, colorArray: [UIColor.appBlue.cgColor, UIColor.appLightBlue.cgColor], type: .axial)
输出:
我做了一个UIView扩展应用一个基本的渐变到任何视图
extension UIView {
func layerGradient() {
let layer : CAGradientLayer = CAGradientLayer()
layer.frame.size = self.frame.size
layer.frame.origin = CGPointMake(0.0,0.0)
layer.cornerRadius = CGFloat(frame.width / 20)
let color0 = UIColor(red:250.0/255, green:250.0/255, blue:250.0/255, alpha:0.5).CGColor
let color1 = UIColor(red:200.0/255, green:200.0/255, blue: 200.0/255, alpha:0.1).CGColor
let color2 = UIColor(red:150.0/255, green:150.0/255, blue: 150.0/255, alpha:0.1).CGColor
let color3 = UIColor(red:100.0/255, green:100.0/255, blue: 100.0/255, alpha:0.1).CGColor
let color4 = UIColor(red:50.0/255, green:50.0/255, blue:50.0/255, alpha:0.1).CGColor
let color5 = UIColor(red:0.0/255, green:0.0/255, blue:0.0/255, alpha:0.1).CGColor
let color6 = UIColor(red:150.0/255, green:150.0/255, blue:150.0/255, alpha:0.1).CGColor
layer.colors = [color0,color1,color2,color3,color4,color5,color6]
self.layer.insertSublayer(layer, atIndex: 0)
}
}
Swift 3 -只使用纹理和SKSpriteNode，不需要UIView
import Foundation
import SpriteKit
class GradientSpriteNode : SKSpriteNode
{
convenience init(size: CGSize, colors: [UIColor], locations: [CGFloat])
{
let texture = GradientSpriteNode.texture(size: size, colors: colors, locations: locations)
self.init(texture: texture, color:SKColor.clear, size: texture.size())
}
private override init(texture: SKTexture!, color: SKColor, size: CGSize) {
super.init(texture: texture, color: color, size: size)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
private static func texture(size: CGSize, colors: [UIColor], locations: [CGFloat]) -> SKTexture
{
UIGraphicsBeginImageContext(size)
let context = UIGraphicsGetCurrentContext()!
let gradient = CGGradient(colorsSpace: CGColorSpaceCreateDeviceRGB(), colors: colors.map{$0.cgColor} as CFArray, locations: locations)!
context.drawLinearGradient(gradient, start: CGPoint(x: size.width / 2, y: 0), end: CGPoint(x: size.width / 2, y: size.height), options: CGGradientDrawingOptions())
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return SKTexture(image: image!)
}
}
用法:
let gradient = GradientSpriteNode(
size: CGSize(width: 100, height: 100),
colors: [UIColor.red, UIColor.blue],
locations: [0.0, 1.0])
addChild(gradient)
