Question

我希望能够中断正在对UIImageView进行动画处理的CABasicAnimation并从其原始起点重新开始，但是如果这样做，它会完全消失。

在我的代码中，我删除了动画和UIIMageView（如果存在），但这是动画完全消失的，直到再次运行代码。因此，每隔一次消失。

如果我在设置的持续时间内运行动画，并让其使用其完成处理程序将其删除，然后再次启动它，则它会重新正常运行。

它可能不会消失，但是会在屏幕外显示，因为它可能会保留其结束动画位置的新设置位置。但是，如果重新定义变量和UIImageView，那是什么原因呢？是CATransaction吗？

if let swipeArrowIMGView:UIImageView = self.view.viewWithTag(viewTags.swipeArrow.rawValue) as? UIImageView {

    swipeArrowIMGView.layer.removeAllAnimations()
    swipeArrowIMGView.removeFromSuperview()

}

let swipeArrowIMG:UIImage = UIImage(named: "swipeArrow")!
let swipeArrowIMGView:UIImageView = UIImageView(image: swipeArrowIMG)
swipeArrowIMGView.tag = viewTags.swipeArrow.rawValue
self.view.addSubview(swipeArrowIMGView)


swipeArrowIMGView.transform = .identity


swipeArrowIMGView.transform = swipeArrowIMGView.transform.translatedBy(x: 75,
                                                                       y: 75)

let animateToX = 75
let animateToY = 200

CATransaction.begin()


let animation = CABasicAnimation(keyPath: "position")

let arrowX:CGFloat = swipeArrowIMGView.layer.position.x
let arrowY:CGFloat = swipeArrowIMGView.layer.position.y


animation.fromValue = [arrowX, arrowY]
animation.toValue =  [animateToX, animateToY]
animation.duration = 1.4
animation.isRemovedOnCompletion = true

swipeArrowIMGView.layer.position = CGPoint(x: animateToX, y: animateToY)

CATransaction.setCompletionBlock{ () in

    if let swipeArrow:UIImageView = self.view.viewWithTag(viewTags.swipeArrow.rawValue) as? UIImageView {
        swipeArrow.removeFromSuperview()
    }

}

swipeArrowIMGView.layer.add(animation, forKey: nil)
CATransaction.commit()

中断CABasicAnimation并让UIImageView从其原始位置开始并重播动画

0 个答案: