我试图在完成块中的动画结束后从父视图中删除自定义视图，但它立即被调用并且动画变得尖锐。我设法以一种不太好的方式解决了这个问题:只是添加了一个延迟来删除视图。
下面是渲染视图的函数:
private func animatedHideSoundView(toRight: Bool) {
let translationX = toRight ? 0.0 : -screenWidth
UIView.animate(withDuration: 0.5) {
self.soundView.transform = CGAffineTransform(translationX: translationX, y: 0.0)
} completion: { isFinished in
if isFinished {
self.soundView.removeFromSuperview()
self.songPlayer.pause()
}
}
}
这一行的问题:self.soundView.removeFromSuperview()
当我在开关识别器中调用这个函数时。状态完成块语句，它执行早期，当其他地方一切正常工作。
@objc private func soundViewPanned(recognizer: UIPanGestureRecognizer) {
let touchPoint = recognizer.location(in: view)
switch recognizer.state {
case .began:
initialOffset = CGPoint(x: touchPoint.x - soundView.center.x, y: touchPoint.y - soundView.center.y)
case .changed:
soundView.center = CGPoint(x: touchPoint.x - initialOffset.x, y: touchPoint.y - initialOffset.y)
if notHiddenSoundViewRect.minX > soundView.frame.minX {
animatedHideSoundView(toRight: false)
} else if notHiddenSoundViewRect.maxX < soundView.frame.maxX {
animatedHideSoundView(toRight: true)
}
case .ended, .cancelled:
let decelerationRate = UIScrollView.DecelerationRate.normal.rawValue
let velocity = recognizer.velocity(in: view)
let projectedPosition = CGPoint(
x: soundView.center.x + project(initialVelocity: velocity.x, decelerationRate: decelerationRate),
y: soundView.center.y + project(initialVelocity: velocity.y, decelerationRate: decelerationRate)
)
let nearestCornerPosition = nearestCorner(to: projectedPosition)
let relativeInitialVelocity = CGVector(
dx: relativeVelocity(forVelocity: velocity.x, from: soundView.center.x, to: nearestCornerPosition.x),
dy: relativeVelocity(forVelocity: velocity.y, from: soundView.center.y, to: nearestCornerPosition.y)
)
let timingParameters = UISpringTimingParameters(dampingRatio: 0.8, initialVelocity: relativeInitialVelocity)
let animator = UIViewPropertyAnimator(duration: 0.5, timingParameters: timingParameters)
animator.addAnimations {
self.soundView.center = nearestCornerPosition
}
animator.startAnimation()
default: break
}
}
我希望用户能够将这个soundView从屏幕上滑动。
这就是为什么我在用户移动soundView时检查它在哪里，这样如果他移动soundView靠近屏幕边缘，我就可以动画地隐藏soundView。
也许我做错了，但是我想不出其他的方法，因为我没有太多的经验。有人能给我一些建议吗?
我设法用这种方法解决了它，但我不喜欢它:
private func animatedHideSoundView(toRight: Bool) {
let translationX = toRight ? 0.0 : -screenWidth
UIView.animate(withDuration: 0.5) {
self.soundView.transform = CGAffineTransform(translationX: translationX, y: 0.0)
}
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
self.soundView.removeFromSuperview()
self.songPlayer.pause()
}
}
输入图片描述
您可以在这里看到并运行所有代码:https://github.com/swiloper/AnimationProblem
注意事项…
首先，在控制器代码中，每次移动触摸时，你都会从平移手势识别器调用animatedHideSoundView()。那不太可能是你想做的。
animatedHideSoundView(toRight: true)你的代码:
private func animatedHideSoundView(toRight: Bool) {
let translationX = toRight ? 0.0 : -screenWidth
UIView.animate(withDuration: 0.5) {
self.soundView.transform = CGAffineTransform(translationX: translationX, y: 0.0)
} completion: { isFinished in
if isFinished {
self.soundView.removeFromSuperview()
self.songPlayer.pause()
}
}
}
设置translationX为Zero…当你尝试动画转换时，动画将占用no time因为你没有改变x.
以下是UniversalTypesViewController类的最小版本(它使用链接的SoundView类):
final class UniversalTypesViewController: UIViewController {
// MARK: Properties
private lazy var soundView = SoundView(frame: CGRect(x: 0, y: 0, width: 80, height: 80))
private let panGestureRecognizer = UIPanGestureRecognizer()
private var initialOffset: CGPoint = .zero
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemYellow
panGestureRecognizer.addTarget(self, action: #selector(soundViewPanned(recognizer:)))
soundView.addGestureRecognizer(panGestureRecognizer)
}
private func animatedShowSoundView() {
// reset soundView's transform
soundView.transform = .identity
// add it to the view
view.addSubview(soundView)
// position soundView near bottom, but past the right side of view
soundView.frame.origin = CGPoint(x: view.frame.width, y: view.frame.height - soundView.frame.height * 2.0)
soundView.startSoundBarsAnimation()
// animate soundView into view
UIView.animate(withDuration: 0.5, delay: 0.0, options: .curveEaseOut) {
self.soundView.transform = CGAffineTransform(translationX: -self.soundView.frame.width * 2.0, y: 0.0)
}
}
private func animatedHideSoundView(toRight: Bool) {
let translationX = toRight ? view.frame.width : -(view.frame.width + soundView.frame.width)
UIView.animate(withDuration: 0.5) {
self.soundView.transform = CGAffineTransform(translationX: translationX, y: 0.0)
} completion: { isFinished in
if isFinished {
self.soundView.removeFromSuperview()
//self.songPlayer.pause()
}
}
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
// if soundView is not in the view hierarchy,
// animate it into view - animatedShowSoundView() func adds it as a subview
if soundView.superview == nil {
animatedShowSoundView()
} else {
// unwrap the touch
guard let touch = touches.first else { return }
// get touch location
let loc = touch.location(in: self.view)
// if touch is inside the soundView frame,
// return, so pan gesture can move soundView
if soundView.frame.contains(loc) { return }
// if touch is on the left-half of the screen,
// animate soundView to the left and remove after animation
if loc.x < view.frame.midX {
animatedHideSoundView(toRight: false)
} else {
// touch is on the right-half of the screen,
// so just remove soundView
animatedHideSoundView(toRight: true)
}
}
}
// MARK: Objc methods
@objc private func soundViewPanned(recognizer: UIPanGestureRecognizer) {
let touchPoint = recognizer.location(in: view)
switch recognizer.state {
case .began:
initialOffset = CGPoint(x: touchPoint.x - soundView.center.x, y: touchPoint.y - soundView.center.y)
case .changed:
soundView.center = CGPoint(x: touchPoint.x - initialOffset.x, y: touchPoint.y - initialOffset.y)
case .ended, .cancelled:
()
default: break
}
}
}
如果你运行这个，点击任何地方都会将soundView动画到右下角的视图中。然后你可以拖动soundView。
如果你点击远离soundView帧，在左半部分的屏幕，soundView将动画出左并在动画完成后删除。
如果你点击远离soundView帧，在右半部分的屏幕，soundView将动画出到右边并在动画完成后删除。
一旦你让它工作了，你看到发生了什么，你可以在你的其他更复杂的代码中实现它。
编辑
看一下修改后的代码。
你的代码中的一个大问题是你多次调用animatedHideSoundView()。当拖拽靠近边缘时，代码调用…但是它会再次被调用因为拖拽仍然处于活动状态。
所以，我添加了一个var isHideAnimationRunning: Bool标志，以便在拖动时调用定位，在"隐藏"动画不要冲突。
其他一些更改:
- 而不是混合变换与
.center定位，去掉变换，只使用.center - 我创建了一个具有逻辑命名角点的结构体-使其更容易引用
- 强烈推荐:在你的代码中添加注释!
那么，试一下:
import UIKit
let screenWidth: CGFloat = UIScreen.main.bounds.width
let screenHeight: CGFloat = UIScreen.main.bounds.height
let sideSpacing: CGFloat = 32.0
let mediumSpacing: CGFloat = 16.0
var isNewIphone: Bool {
return screenHeight / screenWidth > 1.8
}
extension CGPoint {
func distance(to point: CGPoint) -> CGFloat {
return sqrt(pow(point.x - x, 2) + pow(point.y - y, 2))
}
}
// so we can refer to corner positions by logical names
struct CornerPoints {
var topLeft: CGPoint = .zero
var bottomLeft: CGPoint = .zero
var bottomRight: CGPoint = .zero
var topRight: CGPoint = .zero
}
final class ViewController: UIViewController {
private var cornerPoints = CornerPoints()
private let soundViewSide: CGFloat = 80.0
private lazy var halfSoundViewWidth = soundViewSide / 2
private lazy var newIphoneSpacing = isNewIphone ? mediumSpacing : 0.0
private lazy var soundView = SoundView(frame: CGRect(origin: .zero, size: CGSize(width: soundViewSide, height: soundViewSide)))
private lazy var notHiddenSoundViewRect = CGRect(x: mediumSpacing, y: 0.0, width: screenWidth - mediumSpacing * 2, height: screenHeight)
private var initialOffset: CGPoint = .zero
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .yellow
// setup corner points
let left = sideSpacing + halfSoundViewWidth
let right = view.frame.maxX - (sideSpacing + halfSoundViewWidth)
let top = sideSpacing + halfSoundViewWidth - newIphoneSpacing
let bottom = view.frame.maxY - (sideSpacing + halfSoundViewWidth - newIphoneSpacing)
cornerPoints.topLeft = CGPoint(x: left, y: top)
cornerPoints.bottomLeft = CGPoint(x: left, y: bottom)
cornerPoints.bottomRight = CGPoint(x: right, y: bottom)
cornerPoints.topRight = CGPoint(x: right, y: top)
let panGestureRecognizer = UIPanGestureRecognizer()
panGestureRecognizer.addTarget(self, action: #selector(soundViewPanned(recognizer:)))
soundView.addGestureRecognizer(panGestureRecognizer)
// for development, let's add a double-tap recognizer to
// add the soundView again (if it's been removed)
let dt = UITapGestureRecognizer(target: self, action: #selector(showAgain(_:)))
dt.numberOfTapsRequired = 2
view.addGestureRecognizer(dt)
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
self.animatedShowSoundView()
}
}
@objc func showAgain(_ f: UITapGestureRecognizer) {
// if soundView has been removed
if soundView.superview == nil {
// add it
animatedShowSoundView()
}
}
private func animatedShowSoundView() {
// start at bottom-right, off-screen to the right
let pt: CGPoint = cornerPoints.bottomRight
soundView.center = CGPoint(x: screenWidth + soundViewSide, y: pt.y)
view.addSubview(soundView)
soundView.startSoundBarsAnimation()
// animate to bottom-right corner
UIView.animate(withDuration: 0.5, delay: 0.0, options: .curveEaseOut) {
self.soundView.center = pt
}
}
// flag so we know if soundView is currently
// "hide" animating
var isHideAnimationRunning: Bool = false
private func animatedHideSoundView(toRight: Bool) {
// only execute if soundView is not currently "hide" animating
if !isHideAnimationRunning {
// set flag to true
isHideAnimationRunning = true
// target center X
let targetX: CGFloat = toRight ? screenWidth + soundViewSide : -soundViewSide
UIView.animate(withDuration: 0.5) {
self.soundView.center.x = targetX
} completion: { isFinished in
self.isHideAnimationRunning = false
if isFinished {
self.soundView.removeFromSuperview()
//self.songPlayer.pause()
}
}
}
}
@objc private func soundViewPanned(recognizer: UIPanGestureRecognizer) {
let touchPoint = recognizer.location(in: view)
switch recognizer.state {
case .began:
// only execute if soundView is not currently "hide" animating
if !isHideAnimationRunning {
initialOffset = CGPoint(x: touchPoint.x - soundView.center.x, y: touchPoint.y - soundView.center.y)
}
case .changed:
// only execute if soundView is not currently "hide" animating
if !isHideAnimationRunning {
soundView.center = CGPoint(x: touchPoint.x - initialOffset.x, y: touchPoint.y - initialOffset.y)
if notHiddenSoundViewRect.minX > soundView.frame.minX {
animatedHideSoundView(toRight: false)
} else if notHiddenSoundViewRect.maxX < soundView.frame.maxX {
animatedHideSoundView(toRight: true)
}
}
case .ended, .cancelled:
// only execute if soundView is not currently "hide" animating
if !isHideAnimationRunning {
let decelerationRate = UIScrollView.DecelerationRate.normal.rawValue
let velocity = recognizer.velocity(in: view)
let projectedPosition = CGPoint(
x: soundView.center.x + project(initialVelocity: velocity.x, decelerationRate: decelerationRate),
y: soundView.center.y + project(initialVelocity: velocity.y, decelerationRate: decelerationRate)
)
let nearestCornerPosition = nearestCorner(to: projectedPosition)
let relativeInitialVelocity = CGVector(
dx: relativeVelocity(forVelocity: velocity.x, from: soundView.center.x, to: nearestCornerPosition.x),
dy: relativeVelocity(forVelocity: velocity.y, from: soundView.center.y, to: nearestCornerPosition.y)
)
let timingParameters = UISpringTimingParameters(dampingRatio: 0.8, initialVelocity: relativeInitialVelocity)
let animator = UIViewPropertyAnimator(duration: 0.5, timingParameters: timingParameters)
animator.addAnimations {
self.soundView.center = nearestCornerPosition
}
animator.startAnimation()
}
default: break
}
}
private func project(initialVelocity: CGFloat, decelerationRate: CGFloat) -> CGFloat {
return (initialVelocity / 1000) * decelerationRate / (1 - decelerationRate)
}
private func nearestCorner(to point: CGPoint) -> CGPoint {
var minDistance = CGFloat.greatestFiniteMagnitude
var nearestPosition = CGPoint.zero
for position in [cornerPoints.topLeft, cornerPoints.bottomLeft, cornerPoints.bottomRight, cornerPoints.topRight] {
let distance = point.distance(to: position)
if distance < minDistance {
nearestPosition = position
minDistance = distance
}
}
return nearestPosition
}
/// Calculates the relative velocity needed for the initial velocity of the animation.
private func relativeVelocity(forVelocity velocity: CGFloat, from currentValue: CGFloat, to targetValue: CGFloat) -> CGFloat {
guard currentValue - targetValue != 0 else { return 0 }
return velocity / (targetValue - currentValue)
}
}