Swift : 暂停 CALayer 的 CABasicAnimation
Swift : Pause CABasicAnimation for CALayer
您在下面看到的代码创建了一个 CALayer(矩形)并从左到右对其进行动画处理(您可以直接在新项目中复制和粘贴代码):
//Global Variables
var layer = CALayer()
var holdGesture = UILongPressGestureRecognizer()
let animation = CABasicAnimation(keyPath: "bounds.size.width")
func setUpView(){
self.view.addGestureRecognizer(holdGesture)
holdGesture.addTarget(self, action:"handleLongPress:")
}
func handleLongPress(sender : UILongPressGestureRecognizer){
//NEED IT HERE
//var layer = CALayer()
layer.frame = CGRect(x: 0, y: 0, width: 0, height: 10)
layer.backgroundColor = UIColor.redColor().CGColor
animation.fromValue = 0
animation.toValue = self.view.bounds.width * 2
animation.duration = 5
self.view.layer.addSublayer(layer)
if(sender.state == .Began){
print("Long Press Began")
layer.addAnimation(animation, forKey: "bounds.size.width")
}
else{
print("Long press ended")
pauseLayer(layer)
}
}
func pauseLayer(layer : CALayer){
let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), fromLayer: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
override func didReceiveMemoryWarning(){
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
setUpView()
}
我遇到的问题是变量 "layer" 只能暂停(当通过 "pauseLayer" 函数传递时)如果它是一个全局变量!我不知道为什么!我想在 "handleLongPress" function.The 内声明变量,原因是每次识别 longPressGestureRecognizer 时我都需要声明一个同名的新变量。我试过使用 "inout" 通过引用传递,但它似乎没有用。有人可以帮忙吗?请。
使用此修改后的代码:
//Global Variables
var layer: CALayer?
var holdGesture = UILongPressGestureRecognizer()
let animation = CABasicAnimation(keyPath: "bounds.size.width")
func setUpView(){
self.view.addGestureRecognizer(holdGesture)
holdGesture.addTarget(self, action:"handleLongPress:")
}
func handleLongPress(sender : UILongPressGestureRecognizer){
if(sender.state == .Began) {
let newLayer = CALayer()
newLayer.frame = CGRect(x: 0, y: 0, width: 0, height: 10)
newLayer.backgroundColor = UIColor.redColor().CGColor
animation.fromValue = 0
animation.toValue = self.view.bounds.width * 2
animation.duration = 5
self.view.layer.addSublayer(newLayer)
print("Long Press Began")
newLayer.addAnimation(animation, forKey: "bounds.size.width")
layer = newLayer
}
else {
print("Long press ended")
if let layer = layer {
pauseLayer(layer)
layer.removeFromSuperlayer()
}
}
}
func pauseLayer(layer : CALayer){
let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), fromLayer: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
暂停图层
func pauseLayer(layer : CALayer){
let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), from: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
我给你的恢复功能加分:D
func resumeAnimation(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
}
您在下面看到的代码创建了一个 CALayer(矩形)并从左到右对其进行动画处理(您可以直接在新项目中复制和粘贴代码):
//Global Variables
var layer = CALayer()
var holdGesture = UILongPressGestureRecognizer()
let animation = CABasicAnimation(keyPath: "bounds.size.width")
func setUpView(){
self.view.addGestureRecognizer(holdGesture)
holdGesture.addTarget(self, action:"handleLongPress:")
}
func handleLongPress(sender : UILongPressGestureRecognizer){
//NEED IT HERE
//var layer = CALayer()
layer.frame = CGRect(x: 0, y: 0, width: 0, height: 10)
layer.backgroundColor = UIColor.redColor().CGColor
animation.fromValue = 0
animation.toValue = self.view.bounds.width * 2
animation.duration = 5
self.view.layer.addSublayer(layer)
if(sender.state == .Began){
print("Long Press Began")
layer.addAnimation(animation, forKey: "bounds.size.width")
}
else{
print("Long press ended")
pauseLayer(layer)
}
}
func pauseLayer(layer : CALayer){
let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), fromLayer: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
override func didReceiveMemoryWarning(){
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
setUpView()
}
我遇到的问题是变量 "layer" 只能暂停(当通过 "pauseLayer" 函数传递时)如果它是一个全局变量!我不知道为什么!我想在 "handleLongPress" function.The 内声明变量,原因是每次识别 longPressGestureRecognizer 时我都需要声明一个同名的新变量。我试过使用 "inout" 通过引用传递,但它似乎没有用。有人可以帮忙吗?请。
使用此修改后的代码:
//Global Variables
var layer: CALayer?
var holdGesture = UILongPressGestureRecognizer()
let animation = CABasicAnimation(keyPath: "bounds.size.width")
func setUpView(){
self.view.addGestureRecognizer(holdGesture)
holdGesture.addTarget(self, action:"handleLongPress:")
}
func handleLongPress(sender : UILongPressGestureRecognizer){
if(sender.state == .Began) {
let newLayer = CALayer()
newLayer.frame = CGRect(x: 0, y: 0, width: 0, height: 10)
newLayer.backgroundColor = UIColor.redColor().CGColor
animation.fromValue = 0
animation.toValue = self.view.bounds.width * 2
animation.duration = 5
self.view.layer.addSublayer(newLayer)
print("Long Press Began")
newLayer.addAnimation(animation, forKey: "bounds.size.width")
layer = newLayer
}
else {
print("Long press ended")
if let layer = layer {
pauseLayer(layer)
layer.removeFromSuperlayer()
}
}
}
func pauseLayer(layer : CALayer){
let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), fromLayer: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
暂停图层
func pauseLayer(layer : CALayer){
let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), from: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
我给你的恢复功能加分:D
func resumeAnimation(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
}