UIBezierPath 动画 - 对象固定在左上角
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【中文标题】UIBezierPath 动画 - 对象固定在左上角【英文标题】:Animation with UIBezierPath - Object gets fixed on the top left corner 【发布时间】:2020-05-07 11:43:37 【问题描述】:我正在尝试快速创建一个动画,以使一些气球从屏幕底部浮动到顶部。然而,在动画的中间,一个气球会固定在屏幕的左上角,即使动画结束也不会消失。
请观看此视频以了解我在说什么:
https://imgur.com/a/tyS0Q5u
这是我的代码。我真的不知道我做错了什么。
func presentVictoryView()
blackView.isHidden = false
for _ in 0 ... 20
let objectView = UIView()
objectView.translatesAutoresizingMaskIntoConstraints = false
objectView.frame = CGRect(x: 50, y: 50, width: 20, height: 100)
//objectView.backgroundColor = .clear
//objectView.alpha = CGFloat(0.9)
objectView.isHidden = false
let ballon = UILabel()
ballon.translatesAutoresizingMaskIntoConstraints = false
ballon.frame = CGRect(x: 50, y: 50, width: 20, height: 100)
//ballon.backgroundColor = .clear
//ballon.alpha = CGFloat(0.9)
ballon.text = "????"
ballon.font = UIFont.systemFont(ofSize: 60)
objectView.addSubview(ballon)
NSLayoutConstraint.activate([
ballon.centerXAnchor.constraint(equalTo: objectView.centerXAnchor),
ballon.centerYAnchor.constraint(equalTo: objectView.centerYAnchor)
])
blackView.addSubview(objectView)
let randomXOffset = Int.random(in: -120 ..< 200)
let path = UIBezierPath()
path.move(to: CGPoint(x: 270 + randomXOffset, y: 1000))
path.addCurve(to: CGPoint(x: 100 + randomXOffset, y: -300), controlPoint1: CGPoint(x: 300 - randomXOffset, y: 600), controlPoint2: CGPoint(x: 70 + randomXOffset, y: 300))
let animation = CAKeyframeAnimation(keyPath: "position")
animation.path = path.cgPath
animation.repeatCount = 1
animation.duration = Double.random(in: 4.0 ..< 7.0)
//animation.timeOffset = Double(arc4random_uniform(50))
objectView.layer.add(animation, forKey: "animate position along path")
//objectView.isHidden = true
//self?.newGame()
感谢您的帮助! :)
【问题讨论】:
【参考方案1】:您应该使用委托来检测动画的结束并删除bubbleView。
func presentVictoryView()
blackView.isHidden = false
for _ in 0 ... 20
let objectView = UIView()
objectView.translatesAutoresizingMaskIntoConstraints = false
objectView.frame = CGRect(x: 50, y: 50, width: 20, height: 100)
//objectView.backgroundColor = .clear
//objectView.alpha = CGFloat(0.9)
objectView.isHidden = false
let ballon = UILabel()
ballon.translatesAutoresizingMaskIntoConstraints = false
ballon.frame = CGRect(x: 50, y: 50, width: 20, height: 100)
//ballon.backgroundColor = .clear
//ballon.alpha = CGFloat(0.9)
ballon.text = "?"
ballon.font = UIFont.systemFont(ofSize: 60)
objectView.addSubview(ballon)
NSLayoutConstraint.activate([
ballon.centerXAnchor.constraint(equalTo: objectView.centerXAnchor),
ballon.centerYAnchor.constraint(equalTo: objectView.centerYAnchor)
])
blackView.addSubview(objectView)
let randomXOffset = Int.random(in: -120 ..< 200)
let path = UIBezierPath()
path.move(to: CGPoint(x: 270 + randomXOffset, y: 1000))
path.addCurve(to: CGPoint(x: 100 + randomXOffset, y: -300), controlPoint1: CGPoint(x: 300 - randomXOffset, y: 600), controlPoint2: CGPoint(x: 70 + randomXOffset, y: 300))
let animation = CAKeyframeAnimation(keyPath: "position")
animation.path = path.cgPath
animation.repeatCount = 1
// add these
animation.fillMode = .forwards
animation.isRemovedOnCompletion = false
let delegate = BubbleAnimDelegate()
delegate.didFinishAnimation =
objectView.removeFromSuperview()
animation.delegate = delegate
// upto here
animation.duration = Double.random(in: 4.0 ..< 7.0)
//animation.timeOffset = Double(arc4random_uniform(50))
objectView.layer.add(animation, forKey: "animate position along path")
//objectView.isHidden = true
//self?.newGame()
class BubbleAnimDelegate: NSObject, CAAnimationDelegate
var didFinishAnimation: (()->Void)?
func animationDidStop(_ anim: CAAnimation, finished flag: Bool)
didFinishAnimation?()
【讨论】:
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