使用UIDynamicBehavior將慣性添加到UIView Pan

Question

我想用UIPanGestureRecognizer平移'blockView'。當平底鍋是'結束'時，想讓'blockView'慣性減速，就像UIScrollView結束慣性滾動一樣。

override func viewDidLoad() { 
    super.viewDidLoad() 
    self.dynamicAnimator = UIDynamicAnimator(referenceView: self.view) 

    let collider = UICollisionBehavior(items: [self.magnifiedView!]) 
    collider.collisionDelegate = self 
    collider.collisionMode = .Boundaries 
    collider.translatesReferenceBoundsIntoBoundary = true 
    self.dynamicAnimator.addBehavior(collider) 

    self.dynamicProperties = UIDynamicItemBehavior(items: [self.magnifiedView!]) 
    //self.dynamicProperties.elasticity = 1.0 
    //self.dynamicProperties.friction = 0.0 
    self.dynamicProperties.allowsRotation = false 
    //self.dynamicProperties.resistance = 10.0 
    self.dynamicAnimator.addBehavior(self.dynamicProperties) 

} 


func panBlockView (panGesture: UIPanGestureRecognizer) { 
    switch panGesture { 
    case .Began: 
     self.blockViewLocation = (self.blockView.center)! 
    case .Changed: 
     let translation = panGesture.translationInView(self.view) 
     self.blockView.center = CGPointMake(self.blockViewLocation.x + translation.x, self.self.blockViewLocation.y + translation.y) 
    case .Ended, .Cancelled: 
     self.dynamicAnimator.addLinearVelocity(panGesture.velocityInView(self.view), forItem: self.blockView) 
    } 
} 

問題： 當我平移視圖， 'BlockView用來' 試圖捕捉到鍋起源於原點。當鍋'結束'時，它會產生慣性，但它從鍋的原點開始（在捕捉到鍋的原點之後）。

注意： 上面的代碼工作沒有問題只是潘視圖。

Answer 1

添加捕捉行爲並使其捕捉修復問題。