我想在动画时重新设置不同颜色的渐变背景动画.
我可以使用此代码成功为渐变颜色设置动画.
我可以使用此代码成功为渐变颜色设置动画.
let dayTopColor = CommonUtils.colorWithHexString("955EAC")
let dayBottomColor = CommonUtils.colorWithHexString("9F3050")
let dayToTopColor = CommonUtils.colorWithHexString("D15B52")
let dayToBottomColor = CommonUtils.colorWithHexString("CC4645")
let nightTopColor = CommonUtils.colorWithHexString("2D5E7C")
let nightBottomColor = CommonUtils.colorWithHexString("19337D")
let nightToTopColor = CommonUtils.colorWithHexString("21334E")
let nightToBottomColor = CommonUtils.colorWithHexString("101A55")
var isInSaudiArabia = false
var gradient : CAGradientLayer?
var toColors : AnyObject?
var fromColors : AnyObject?
func animateBackground(){
var layerToRemove: CAGradientLayer?
for layer in self.view.layer.sublayers!{
if layer.isKindOfClass(CAGradientLayer) {
layerToRemove = layer as? CAGradientLayer
}
}
layerToRemove?.removeFromSuperlayer()
self.gradient!.colors = [nightTopColor.CGColor,nightBottomColor.CGColor]
self.toColors = [nightToTopColor.CGColor,nightToBottomColor.CGColor]
self.view.layer.insertSublayer(self.gradient!,atIndex: 0)
animateLayer()
}
func animateLayer(){
self.fromColors = self.gradient!.colors!
self.gradient!.colors = self.toColors as? [AnyObject]
let animation : CABasicAnimation = CABasicAnimation(keyPath: "colors")
animation.delegate = self
animation.fromValue = fromColors
animation.toValue = toColors
animation.duration = 3.50
animation.removedOnCompletion = true
animation.fillMode = kCAFillModeForwards
animation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionLinear)
animation.delegate = self
self.gradient!.addAnimation(animation,forKey:"animateGradient")
}
override func animationDidStop(anim: CAAnimation,finished flag: Bool) {
self.toColors = self.fromColors;
self.fromColors = self.gradient!.colors!
animateLayer()
}
CommonUtils.colorWithHexString()是一个将十六进制颜色转换为UIColor的函数.
顺便说一句,当我尝试在动画时将背景颜色更改为日间颜色时,背景渐变颜色变得闪烁.
有谁知道解决方案.
解决方法
问题是当你删除图层时,它会停止动画.但是当动画停止时,仍然会调用animationDidStop,这将启动一个新动画本身.所以,你要删除停止动画的图层,立即启动另一个图层,但是你要开始另一个动画.你有决斗动画.
您可以在animationDidStop调用animateLayer之前检查标记以查看动画是否正确完成.
override func animationDidStop(anim: CAAnimation,finished flag: Bool) {
if flag {
toColors = fromColors;
fromColors = gradient!.colors!
animateLayer()
}
}
就个人而言,我不确定你为什么要删除,添加和删除图层.如果你是,我不确定为什么你不只是渐变？.removeFromSuperlayer()而不是迭代层.
无论如何,我只是将渐变层保留在那里,只需检查其presentationLayer并从那里开始动画：
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
fromColors = [dayTopColor.CGColor,dayBottomColor.CGColor]
toColors = [dayToTopColor.CGColor,dayToBottomColor.CGColor]
gradient = CAGradientLayer()
gradient!.colors = fromColors!
gradient!.frame = view.bounds
view.layer.addSublayer(gradient!)
animateLayer()
}
let dayTopColor = CommonUtils.colorWithHexString("955EAC")
let dayBottomColor = CommonUtils.colorWithHexString("9F3050")
let dayToTopColor = CommonUtils.colorWithHexString("D15B52")
let dayToBottomColor = CommonUtils.colorWithHexString("CC4645")
let nightTopColor = CommonUtils.colorWithHexString("2D5E7C")
let nightBottomColor = CommonUtils.colorWithHexString("19337D")
let nightToTopColor = CommonUtils.colorWithHexString("21334E")
let nightToBottomColor = CommonUtils.colorWithHexString("101A55")
var gradient : CAGradientLayer?
var toColors : [CGColor]?
var fromColors : [CGColor]?
var day = true
func toggleFromDayToNight() {
day = !day
if day {
fromColors = [dayTopColor.CGColor,dayBottomColor.CGColor]
toColors = [dayToTopColor.CGColor,dayToBottomColor.CGColor]
} else {
fromColors = [nightTopColor.CGColor,nightBottomColor.CGColor]
toColors = [nightToTopColor.CGColor,nightToBottomColor.CGColor]
}
let colors = (gradient!.presentationLayer() as! CAGradientLayer).colors // save the in-flight current colors
gradient!.removeAnimationForKey("animateGradient") // cancel the animation
gradient!.colors = colors // restore the colors to in-flight values
animateLayer() // start animation
}
func animateLayer() {
let animation : CABasicAnimation = CABasicAnimation(keyPath: "colors")
animation.fromValue = gradient!.colors
animation.toValue = toColors
animation.duration = 3.50
animation.removedOnCompletion = true
animation.fillMode = kCAFillModeForwards
animation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionLinear)
animation.delegate = self
gradient!.colors = toColors
gradient!.addAnimation(animation,finished flag: Bool) {
if flag {
swap(&toColors,&fromColors)
animateLayer()
}
}
@IBAction func didTapButton() {
toggleFromDayToNight()
}
}
