带有平移、旋转和捏合手势的 UIKit Dynamics
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【中文标题】带有平移、旋转和捏合手势的 UIKit Dynamics【英文标题】:UIKit Dynamics with pan, rotate and pinch gesture 【发布时间】:2017-07-06 12:32:06 【问题描述】:我已将 UIDynamics 添加到 imageview 并为此使用了平移手势。使用平移手势可以正常工作,但是当我应用捏合手势时它不起作用。它显示大图像视图,但是当我开始拖动时,它会更改为原始大小。
这是我的代码:
func handleAttachmentGesture(_ sender: UIPanGestureRecognizer)
let location = sender.location(in: emojiSuperView!)
let boxLocation = sender.location(in: self)
switch sender.state
case .began:
print("Your touch start position is \(location)")
print("Start location in image is \(boxLocation)")
animator.removeAllBehaviors()
let centerOffset = UIOffset(horizontal: boxLocation.x - self.bounds.midX, vertical: boxLocation.y - self.bounds.midY)
attachmentBehavior = UIAttachmentBehavior(item: self, offsetFromCenter: centerOffset, attachedToAnchor: location)
animator.addBehavior(attachmentBehavior)
case .ended:
print("Your touch end position is \(location)")
print("End location in image is \(boxLocation)")
animator.removeAllBehaviors()
// 1
let velocity = sender.velocity(in: emojiSuperView!)
let magnitude = sqrt((velocity.x * velocity.x) + (velocity.y * velocity.y))
if magnitude > ThrowingThreshold
// 2
let pushBehavior = UIPushBehavior(items: [self], mode: .instantaneous)
pushBehavior.pushDirection = CGVector(dx: velocity.x / 10, dy: velocity.y / 10)
pushBehavior.magnitude = magnitude / ThrowingVelocityPadding
self.pushBehavior = pushBehavior
animator.addBehavior(pushBehavior)
// 3
let angle = Int(arc4random_uniform(20)) - 10
itemBehavior = UIDynamicItemBehavior(items: [self])
itemBehavior.friction = 0.2
itemBehavior.allowsRotation = true
itemBehavior.addAngularVelocity(CGFloat(angle), for: self)
animator.addBehavior(itemBehavior)
default:
attachmentBehavior.anchorPoint = sender.location(in: emojiSuperView!)
break
func recognizePinchGesture(sender: UIPinchGestureRecognizer)
weak var dynamicItem: UIDynamicItem?
// whatever your item is, probably a UIView
dynamicItem = self
let behavior = UIGravityBehavior(items: [dynamicItem!])
let animator = UIDynamicAnimator(referenceView: emojiSuperView!)
// or however you're getting your animator
animator.addBehavior(behavior)
sender.view!.transform = sender.view!.transform.scaledBy(x: sender.scale, y: sender.scale)
animator.updateItem(usingCurrentState: self)
self.animator.updateItem(usingCurrentState: self)
sender.scale = 1
【问题讨论】:
好问题 +1 ???? ,我也面临同样的问题, 您的视图控制器看起来如何?你有公开的吗? 【参考方案1】:当用户执行任何变换事件时,将当前变换保存到全局变量。
之后,当平移开始时,使用 UIAttachmentBehavior 的 action 属性在开始状态下分配新的变换。
attachmentBehavior.action =
self.attachmentBehavior.items[0].transform = self.aTransform
【讨论】:
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