如何將Gradient應用于iOS Swift App的后臺視圖我正在嘗試應用漸變作為視圖的背景顏色（故事板的主視圖）。代碼運行，但沒有任何變化。我正在使用xCode Beta 2和Swift。這是代碼：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]
}}然后在視圖控制器中： let colors = Colors()
func refresh() {
view.backgroundColor = UIColor.clearColor()
var backgroundLayer = colors.gl
backgroundLayer.frame = view.frame
view.layer.insertSublayer(backgroundLayer, atIndex: 0)
}
}
}
3 回答
LEATH
TA貢獻1936條經驗 獲得超7個贊
Xcode 8.2?Swift 3.0.2
您可以設計自己的漸變視圖，如下所示：
@IBDesignableclass GradientView: UIView {
@IBInspectable var startColor: UIColor = .black { didSet { updateColors() }}
@IBInspectable var endColor: UIColor = .white { didSet { updateColors() }}
@IBInspectable var startLocation: Double = 0.05 { didSet { updateLocations() }}
@IBInspectable var endLocation: Double = 0.95 { didSet { updateLocations() }}
@IBInspectable var horizontalMode: Bool = false { didSet { updatePoints() }}
@IBInspectable var diagonalMode: Bool = false { didSet { updatePoints() }}
override public class var layerClass: AnyClass { return CAGradientLayer.self }
var gradientLayer: CAGradientLayer { return layer as! CAGradientLayer }
func updatePoints() {
if horizontalMode {
gradientLayer.startPoint = diagonalMode ? CGPoint(x: 1, y: 0) : CGPoint(x: 0, y: 0.5)
gradientLayer.endPoint = diagonalMode ? CGPoint(x: 0, y: 1) : CGPoint(x: 1, y: 0.5)
} else {
gradientLayer.startPoint = diagonalMode ? CGPoint(x: 0, y: 0) : CGPoint(x: 0.5, y: 0)
gradientLayer.endPoint = diagonalMode ? CGPoint(x: 1, y: 1) : CGPoint(x: 0.5, y: 1)
}
}
func updateLocations() {
gradientLayer.locations = [startLocation as NSNumber, endLocation as NSNumber]
}
func updateColors() {
gradientLayer.colors = [startColor.cgColor, endColor.cgColor]
}
override public func layoutSubviews() {
super.layoutSubviews()
updatePoints()
updateLocations()
updateColors()
}}
慕的地10843
TA貢獻1785條經驗 獲得超8個贊
如果您需要更改漸變的方向，則必須使用startPoint和endPoint。
let gradient: CAGradientLayer = CAGradientLayer()gradient.colors = [UIColor.blue.cgColor, UIColor.red.cgColor]gradient.locations = [0.0 , 1.0]gradient.startPoint = CGPoint(x: 0.0, y: 1.0)gradient.endPoint = CGPoint(x: 1.0, y: 1.0)gradient.frame = CGRect(x: 0.0, y: 0.0, width: self.view.frame.size.width, height: self.view.frame.size.height)self.view.layer.insertSublayer(gradient, atIndex: 0)
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