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动画CAShapeLayer / CAGradientLayer

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这是我昨天问过的一个问题的补充 . 结果很完美，但我想修改一下 . Using drawRect to draw & animate two graphs. A background graph, and a foreground graph

以下代码基于上面的线程生成一个CABasicAnimation，它会生成深蓝色的“三角形” . 而不是深蓝色的纯色，我希望这是一个3站的CAGradientLayer：红色/绿色/蓝色 .

我尝试添加CAGradientLayer来配置渐变，然后使用addSubLayer将渐变添加到动画的CAShapeLayer中 . 我在下面发布的结果不是动画 . 颜色和形状保持不变 . 渐变看起来很棒，只需要它来制作动画：

enter image description here

import UIKit
import QuartzCore
import XCPlayground

let view = UIView(frame: CGRect(x: 0, y: 0, width: 521, height: 40))
view.backgroundColor = UIColor.whiteColor()
XCPlaygroundPage.currentPage.liveView = view

let maskPath = UIBezierPath()

maskPath.moveToPoint(CGPoint(x: 0, y: 30))
maskPath.addLineToPoint(CGPoint(x: 0, y: 25))
maskPath.addLineToPoint(CGPoint(x: 300, y: 10))
maskPath.addLineToPoint(CGPoint(x: 300, y: 30))
maskPath.closePath()

let maskLayer = CAShapeLayer()
maskLayer.path = maskPath.CGPath
maskLayer.fillColor = UIColor.whiteColor().CGColor

let rectToAnimateFrom = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 0, height: 40))
let rectToAnimateTo = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 97, height: 40))

let backgroundGray = CAShapeLayer()
backgroundGray.path = maskPath.CGPath
backgroundGray.fillColor = UIColor.grayColor().CGColor

let foregroundGradient = CAShapeLayer()
foregroundGradient.mask = maskLayer
foregroundGradient.backgroundColor = UIColor.clearColor().CGColor


let gradientLayer = CAGradientLayer()
gradientLayer.startPoint = CGPointMake(0, 0)
gradientLayer.endPoint = CGPointMake(1, 0)
gradientLayer.frame = maskPath.bounds

let colors = [UIColor.redColor().CGColor, UIColor.greenColor().CGColor, UIColor.blueColor().CGColor]
gradientLayer.colors = colors


foregroundGradient.addSublayer(gradientLayer)


view.layer.addSublayer(backgroundGray)
view.layer.addSublayer(foregroundGradient)


let animation = CABasicAnimation(keyPath: "path")
animation.fromValue = rectToAnimateFrom.CGPath
animation.toValue = rectToAnimateTo.CGPath
animation.duration = 2
animation.removedOnCompletion = false
animation.fillMode = kCAFillModeForwards


foregroundGradient.addAnimation(animation, forKey: nil)

I need the foregroundGradient object (with the gradientLayer sublayer!) to animate from left to right.

如果从我上面的代码中删除渐变，并将foregroundGradient保持为纯色，您将看到动画 .

ios swift jquery-animate cagradientlayer

1 回答

  • 2

    我认为你必须在你的视图中使用 mask ，如下所述 .

    //Remove below line
view.layer.addSublayer(backgroundGray)

//Add your mask to view
view.layer.mask = backgroundGray

    the whole function looks like this:

    func getGradientView() {
    let view = UIView(frame: CGRect(x: 0, y: 50, width: 521, height: 40))
    view.backgroundColor = UIColor.grayColor()
    self.view.addSubview(view)

    let maskPath = UIBezierPath()

    maskPath.moveToPoint(CGPoint(x: 0, y: 30))
    maskPath.addLineToPoint(CGPoint(x: 0, y: 25))
    maskPath.addLineToPoint(CGPoint(x: 300, y: 10))
    maskPath.addLineToPoint(CGPoint(x: 300, y: 30))
    maskPath.closePath()

    let maskLayer = CAShapeLayer()
    maskLayer.path = maskPath.CGPath
    maskLayer.fillColor = UIColor.whiteColor().CGColor

    let rectToAnimateFrom = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 0, height: 40))
    let rectToAnimateTo = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 300, height: 40))

    let backgroundGray = CAShapeLayer()
    backgroundGray.path = maskPath.CGPath
    backgroundGray.fillColor = UIColor.grayColor().CGColor

    let foregroundGradient = CAShapeLayer()
    foregroundGradient.mask = maskLayer
    foregroundGradient.backgroundColor = UIColor.clearColor().CGColor


    let gradientLayer = CAGradientLayer()
    gradientLayer.startPoint = CGPointMake(0, 0)
    gradientLayer.endPoint = CGPointMake(1, 0)
    gradientLayer.frame = maskPath.bounds

    let colors = [UIColor.redColor().CGColor, UIColor.greenColor().CGColor, UIColor.blueColor().CGColor]
    gradientLayer.colors = colors

    foregroundGradient.addSublayer(gradientLayer)

    //Remove below line
    //view.layer.addSublayer(backgroundGray)

    view.layer.addSublayer(foregroundGradient)

    //Add you mask to view
    view.layer.mask = backgroundGray

    let animation = CABasicAnimation(keyPath: "path")
    animation.fromValue = rectToAnimateFrom.CGPath
    animation.toValue = rectToAnimateTo.CGPath
    animation.duration = 1
    animation.repeatCount = 1000
    animation.removedOnCompletion = false
    animation.fillMode = kCAFillModeForwards


    maskLayer.addAnimation(animation, forKey: "fill animation")
}

    如果它按照您的例外情况工作，请告诉我 .

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