【发布时间】：2023-09-25 05:37:01
【问题描述】：
参考this 帖子，我正在尝试将动画调整为横向模式。基本上我想要的是旋转-90°（顺时针90°）的所有图层，并且动画水平运行而不是垂直运行。作者没有费心解释背后的逻辑，obj-c 中有十几个纸折叠库，它们都是基于相同的架构，所以显然这是折叠的方式。
编辑：为了进一步阐明我想要实现的目标，here 你可以查看我想要的动画的三个快照（起点、半场和终点）。在上面链接的问题中，动画从下到上折叠，而我希望它从左到右折叠。
您可以在下面查看原始项目，稍作调整：
- 我改变了灰色
bottomSleeve层的最终角度值，以及红色和蓝色的角度； - 我通过设置
perspectiveLayerspeed等于0来暂停动画初始化并添加一个滑块，然后将滑块值设置为等于perspectiveLayertimeOffset以便您可以交互地运行每个通过滑动动画帧。当滑块上的触摸事件结束时，动画会从相对于当前timeOffset的帧恢复到最终值。 - 在运行每个使用
CATransaction添加到相关表示层的动画之前，我更改了所有模型层的值。此外，在完成时，perspectiveLayer速度再次设置为0。 - 为了更好的视觉理解，我将
perspectiveLayerbackgroundColor设置为等于cyan。
只是指出，有两个主要功能：
-
setupLayers()，在viewDidLoad()中调用，负责设置图层位置和锚点，并将它们作为子图层添加到mainView图层。 -
animate()，在setupLayers()中递归调用，负责添加动画。在这里，我还将模型层的值设置为相关动画的最终值，然后再添加它们。
只需复制、粘贴并运行：
class ViewController: UIViewController {
var transform: CATransform3D = CATransform3DIdentity
var topSleeve: CALayer = CALayer()
var middleSleeve: CALayer = CALayer()
var bottomSleeve: CALayer = CALayer()
var topShadow: CALayer = CALayer()
var middleShadow: CALayer = CALayer()
let width: CGFloat = 300
let height: CGFloat = 150
var firstJointLayer: CATransformLayer = CATransformLayer()
var secondJointLayer:CATransformLayer = CATransformLayer()
var sizeHeight: CGFloat = 0
var positionY: CGFloat = 0
var perspectiveLayer: CALayer = {
let perspectiveLayer = CALayer()
perspectiveLayer.speed = 0.0
perspectiveLayer.fillMode = .removed
return perspectiveLayer
}()
var mainView: UIView = {
let view = UIView()
return view
}()
private let slider: UISlider = {
let slider = UISlider()
slider.addTarget(self, action: #selector(slide(sender:event:)) , for: .valueChanged)
return slider
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(slider)
setupLayers()
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
slider.frame = CGRect(x: view.bounds.size.width/3,
y: view.bounds.size.height/10*8,
width: view.bounds.size.width/3,
height: view.bounds.size.height/10)
}
@objc private func slide(sender: UISlider, event: UIEvent) {
if let touchEvent = event.allTouches?.first {
switch touchEvent.phase {
case .ended:
resumeLayer(layer: perspectiveLayer)
default:
perspectiveLayer.timeOffset = CFTimeInterval(sender.value)
}
}
}
private func resumeLayer(layer: CALayer) {
let pausedTime = layer.timeOffset
layer.speed = 1.0
layer.timeOffset = 0.0
layer.beginTime = 0.0
let timeSincePause = layer.convertTime(CACurrentMediaTime(), from: nil) - pausedTime
layer.beginTime = timeSincePause
}
private func setupLayers() {
mainView = UIView(frame:CGRect(x: 50, y: 50, width: width, height: height*3))
mainView.backgroundColor = UIColor.yellow
view.addSubview(mainView)
perspectiveLayer.frame = CGRect(x: 0, y: 0, width: width, height: height*2)
perspectiveLayer.backgroundColor = UIColor.cyan.cgColor
mainView.layer.addSublayer(perspectiveLayer)
firstJointLayer.fillMode = .removed
firstJointLayer.frame = mainView.bounds
perspectiveLayer.addSublayer(firstJointLayer)
topSleeve.fillMode = .removed
topSleeve.frame = CGRect(x: 0, y: 0, width: width, height: height)
topSleeve.anchorPoint = CGPoint(x: 0.5, y: 0)
topSleeve.backgroundColor = UIColor.red.cgColor
topSleeve.position = CGPoint(x: width/2, y: 0)
firstJointLayer.addSublayer(topSleeve)
topSleeve.masksToBounds = true
secondJointLayer.fillMode = .removed
secondJointLayer.frame = mainView.bounds
secondJointLayer.frame = CGRect(x: 0, y: 0, width: width, height: height*2)
secondJointLayer.anchorPoint = CGPoint(x: 0.5, y: 0)
secondJointLayer.position = CGPoint(x: width/2, y: height)
firstJointLayer.addSublayer(secondJointLayer)
secondJointLayer.fillMode = .removed
middleSleeve.frame = CGRect(x: 0, y: 0, width: width, height: height)
middleSleeve.anchorPoint = CGPoint(x: 0.5, y: 0)
middleSleeve.backgroundColor = UIColor.blue.cgColor
middleSleeve.position = CGPoint(x: width/2, y: 0)
secondJointLayer.addSublayer(middleSleeve)
middleSleeve.masksToBounds = true
bottomSleeve.fillMode = .removed
bottomSleeve.frame = CGRect(x: 0, y: height, width: width, height: height)
bottomSleeve.anchorPoint = CGPoint(x: 0.5, y: 0)
bottomSleeve.backgroundColor = UIColor.gray.cgColor
bottomSleeve.position = CGPoint(x: width/2, y: height)
secondJointLayer.addSublayer(bottomSleeve)
firstJointLayer.anchorPoint = CGPoint(x: 0.5, y: 0)
firstJointLayer.position = CGPoint(x: width/2, y: 0)
topShadow.fillMode = .removed
topSleeve.addSublayer(topShadow)
topShadow.frame = topSleeve.bounds
topShadow.backgroundColor = UIColor.black.cgColor
topShadow.opacity = 0
middleShadow.fillMode = .removed
middleSleeve.addSublayer(middleShadow)
middleShadow.frame = middleSleeve.bounds
middleShadow.backgroundColor = UIColor.black.cgColor
middleShadow.opacity = 0
transform.m34 = -1/700
perspectiveLayer.sublayerTransform = transform
sizeHeight = perspectiveLayer.bounds.size.height
positionY = perspectiveLayer.position.y
animate()
}
private func animate() {
CATransaction.begin()
CATransaction.setDisableActions(true)
CATransaction.setCompletionBlock{ [weak self] in
if self == nil { return }
self?.perspectiveLayer.speed = 0
}
firstJointLayer.transform = CATransform3DMakeRotation(CGFloat(-85*Double.pi/180), 1, 0, 0)
secondJointLayer.transform = CATransform3DMakeRotation(CGFloat(170*Double.pi/180), 1, 0, 0)
bottomSleeve.transform = CATransform3DMakeRotation(CGFloat(-165*Double.pi/180), 1, 0, 0)
perspectiveLayer.bounds.size.height = 0
perspectiveLayer.position.y = 0
topShadow.opacity = 0.5
middleShadow.opacity = 0.5
var animation = CABasicAnimation(keyPath: "transform.rotation.x")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = -85*Double.pi/180
firstJointLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "transform.rotation.x")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = 170*Double.pi/180
secondJointLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "transform.rotation.x")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = -165*Double.pi/180
bottomSleeve.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "bounds.size.height")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = sizeHeight
animation.toValue = 0
perspectiveLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "position.y")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = positionY
animation.toValue = 0
perspectiveLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "opacity")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = 0.5
topShadow.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "opacity")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = 0.5
middleShadow.add(animation, forKey: nil)
CATransaction.commit()
}
}
正如您所见，动画按预期运行，此时要旋转整个物体，只需更改位置、锚点和最终动画值即可。 摘自上面链接的答案，这里是起始项目所有层的一个很好的表示：
然后我继续重构 setupLayers() 和 animate() 以从左到右水平运行动画（换句话说，我在上面的图层表示中顺时针旋转 90°）。
更改代码以旋转动画后，我遇到了两个问题：
-
当动画开始时，
firstJointLayer位置沿perspectiveLayer从左向右平移。公平地说，这应该是一种预期的行为，因为它是perspectiveLayer的子层，实际上我不确定为什么在原始项目中它不会发生。但是，为了解决这个问题，我添加了另一个动画，负责在其相关系统中将其从右向左平移，以便它实际上看起来是静止的。此时，虽然我没有更改模型层的最终值（下方项目中的注释行），但动画按预期水平运行。如果我不必同时修改模型层，我的目标就会达到，因为这正是我想要的动画。不过…… -
...如果我尝试设置动画的最终值（只需将这些行注释掉），我会得到意想不到的行为。在动画的初始帧，红色、蓝色和灰色层看起来相互折叠，因此旋转不再像预期的那样工作。以下是时间 0.0、0.5 和 1.0（持续时间：1.0）的一些快照：
对我来说最不合逻辑的部分是，将模型层的值设置为表示层的最终值会导致错误，但它只会影响表示层，因为一旦动画结束，下面的模型层就会在预期中 (和想要的）旋转/位置：
当旋转围绕正确的点进行时，锚点肯定是正确放置的。我认为这可能与问题 1 有关，但我尝试多次重新定位图层但没有成功。直到今天，这仍然没有解决，两天后我无法找到主要问题并因此修复它。对我来说，原始项目（上图）和旋转后的项目（下图）在引擎盖下的逻辑看起来是一样的。
EDIT2：我发现了代码中的一个小错误，我是从等于 perspectiveLayer x 位置而不是他自己的 x 位置的起始值为 firstJointLayer x 位置设置动画，我'已修复，但没有任何改变。
EDIT3：由于将模型层的值设置为等于动画最终值是导致错误的原因，请注意使用animation.fillMode = CAMediaTimingFillMode.forwards 和animation.isRemovedOnCompletion = false 不是避免触摸的可行解决方法模态层，因为我需要稍后恢复动画，因此需要保持演示层和模型层同步。
非常感谢任何帮助。下面是旋转项目 - 我还评论了我从上面的项目中更改的块：
class ViewController: UIViewController {
var transform: CATransform3D = CATransform3DIdentity
var topSleeve: CALayer = CALayer()
var middleSleeve: CALayer = CALayer()
var bottomSleeve: CALayer = CALayer()
var topShadow: CALayer = CALayer()
var middleShadow: CALayer = CALayer()
let width: CGFloat = 200
let height: CGFloat = 300
var firstJointLayer: CALayer = CATransformLayer()
var secondJointLayer: CALayer = CATransformLayer()
var sizeWidth: CGFloat = 0
var positionX: CGFloat = 0
var firstJointLayerPositionX: CGFloat = 0
var perspectiveLayer: CALayer = {
let perspectiveLayer = CALayer()
perspectiveLayer.speed = 0.0
perspectiveLayer.fillMode = .removed
return perspectiveLayer
}()
var mainView: UIView = {
let view = UIView()
return view
}()
private let slider: UISlider = {
let slider = UISlider()
slider.addTarget(self, action: #selector(slide(sender:event:)) , for: .valueChanged)
return slider
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(slider)
setupLayers()
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
slider.frame = CGRect(x: view.bounds.size.width/3,
y: view.bounds.size.height/10*8,
width: view.bounds.size.width/3,
height: view.bounds.size.height/10)
}
@objc private func slide(sender: UISlider, event: UIEvent) {
if let touchEvent = event.allTouches?.first {
switch touchEvent.phase {
case .ended:
resumeLayer(layer: perspectiveLayer)
default:
perspectiveLayer.timeOffset = CFTimeInterval(sender.value)
}
}
}
private func resumeLayer(layer: CALayer) {
let pausedTime = layer.timeOffset
layer.speed = 1.0
layer.timeOffset = 0.0
layer.beginTime = 0.0
let timeSincePause = layer.convertTime(CACurrentMediaTime(), from: nil) - pausedTime
layer.beginTime = timeSincePause
}
private func setupLayers() {
// Changing all anchor points and positions here, in order to rotate the whole thing of -90°
mainView = UIView(frame:CGRect(x: 50, y: 50, width: width*3, height: height))
mainView.backgroundColor = UIColor.yellow
view.addSubview(mainView)
perspectiveLayer.frame = CGRect(x: width, y: 0, width: width*2, height: height)
perspectiveLayer.backgroundColor = UIColor.cyan.cgColor
mainView.layer.addSublayer(perspectiveLayer)
firstJointLayer.fillMode = .removed
firstJointLayer.frame = mainView.bounds
firstJointLayer.anchorPoint = CGPoint(x: 1, y: 0.5)
firstJointLayer.position = CGPoint(x: width*2, y: height/2)
perspectiveLayer.addSublayer(firstJointLayer)
topSleeve.fillMode = .removed
topSleeve.frame = CGRect(x: 0, y: 0, width: width, height: height)
topSleeve.anchorPoint = CGPoint(x: 1, y: 0.5)
topSleeve.backgroundColor = UIColor.red.cgColor
topSleeve.position = CGPoint(x: width*3, y: height/2)
firstJointLayer.addSublayer(topSleeve)
topSleeve.masksToBounds = true
secondJointLayer.fillMode = .removed
secondJointLayer.frame = mainView.bounds
secondJointLayer.frame = CGRect(x: 0, y: 0, width: width*2, height: height)
secondJointLayer.anchorPoint = CGPoint(x: 1, y: 0.5)
secondJointLayer.position = CGPoint(x: width*2, y: height/2)
firstJointLayer.addSublayer(secondJointLayer)
secondJointLayer.fillMode = .removed
middleSleeve.frame = CGRect(x: 0, y: 0, width: width, height: height)
middleSleeve.anchorPoint = CGPoint(x: 1, y: 0.5)
middleSleeve.backgroundColor = UIColor.blue.cgColor
middleSleeve.position = CGPoint(x: width*2, y: height/2)
secondJointLayer.addSublayer(middleSleeve)
middleSleeve.masksToBounds = true
bottomSleeve.fillMode = .removed
bottomSleeve.frame = CGRect(x: 0, y: 0, width: width, height: height)
bottomSleeve.anchorPoint = CGPoint(x: 1, y: 0.5)
bottomSleeve.backgroundColor = UIColor.gray.cgColor
bottomSleeve.position = CGPoint(x: width, y: height/2)
secondJointLayer.addSublayer(bottomSleeve)
topShadow.fillMode = .removed
topSleeve.addSublayer(topShadow)
topShadow.frame = topSleeve.bounds
topShadow.backgroundColor = UIColor.black.cgColor
topShadow.opacity = 0
middleShadow.fillMode = .removed
middleSleeve.addSublayer(middleShadow)
middleShadow.frame = middleSleeve.bounds
middleShadow.backgroundColor = UIColor.black.cgColor
middleShadow.opacity = 0
transform.m34 = -1/700
perspectiveLayer.sublayerTransform = transform
sizeWidth = perspectiveLayer.bounds.size.width
positionX = perspectiveLayer.position.x
firstJointLayerPositionX = firstJointLayer.position.x
animate()
}
private func animate() {
CATransaction.begin()
CATransaction.setDisableActions(true)
CATransaction.setCompletionBlock{ [weak self] in
if self == nil { return }
self?.perspectiveLayer.speed = 0
}
// firstJointLayer.transform = CATransform3DMakeRotation(CGFloat(-85*Double.pi/180), 0, 1, 0)
// secondJointLayer.transform = CATransform3DMakeRotation(CGFloat(170*Double.pi/180), 0, 1, 0)
// bottomSleeve.transform = CATransform3DMakeRotation(CGFloat(-165*Double.pi/180), 0, 1, 0)
// perspectiveLayer.bounds.size.width = 0
// perspectiveLayer.position.x = 600
// firstJointLayer.position.x = 0
// topShadow.opacity = 0.5
// middleShadow.opacity = 0.5
var animation = CABasicAnimation(keyPath: "transform.rotation.y")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = -85*Double.pi/180
firstJointLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "transform.rotation.y")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = 170*Double.pi/180
secondJointLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "transform.rotation.y")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = -165*Double.pi/180
bottomSleeve.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "bounds.size.width")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = sizeWidth
animation.toValue = 0
perspectiveLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "position.x")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = positionX
animation.toValue = 600
perspectiveLayer.add(animation, forKey: nil)
// As said above, i added this animation which is not included in the original project, as the firstJointLayer was translating his position from left to right along with the perspectiveLayer position, so i make a reverse translation in its relative system so that it is stationary in the mainView system
animation = CABasicAnimation(keyPath: "position.x")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = firstJointLayerPositionX
animation.toValue = 0
firstJointLayer.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "opacity")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = 0.5
topShadow.add(animation, forKey: nil)
animation = CABasicAnimation(keyPath: "opacity")
animation.fillMode = CAMediaTimingFillMode.removed
animation.duration = 1
animation.fromValue = 0
animation.toValue = 0.5
middleShadow.add(animation, forKey: nil)
CATransaction.commit()
}
}
【问题讨论】：
-
不太清楚...留下您的评论行评论，您是否获得了您想要的开始和动画，如下所示：imgur.com/a/0xRXrWP？但是，您的目标是让它“折叠到中心”而不是从左到右折叠？
-
@DonMag 我很抱歉不清楚，我已经编辑了顶部的帖子以显示我想要的动画的一些快照。基本上我想要与注释行完全相同的动画，从左到右折叠（与我从中获取逻辑的链接问题的原始项目相反，其动画从下到上折叠）。这里的问题是，一旦您注释掉这些行，表示层就会变得疯狂，我不知道为什么。
-
hmm... 您在编辑中链接到的图像“我想要的动画” 似乎正是我在运行您的代码时看到的，如图所示我链接到的图片？
-
注释行应该完成什么？问题是动画完成后，它会弹回“平面”并且您希望它保持“折叠”吗？
-
转换是累积的——所以虽然它似乎应该可以工作，但我认为问题在于这种组合并没有真正做到看起来合乎逻辑的事情。如果您的目标是在动画结束时保留变换，请将那些注释行保留注释，并尝试将所有动画设置为
animation.fillMode = CAMediaTimingFillMode.forwards和animation.isRemovedOnCompletion = false
标签： ios swift core-animation calayer cabasicanimation