swift - Swift 中的多个动画过渡

Question

我有一个包含 UIImageView 的嵌套 UIStackView。我希望每个 UIImageView 翻转以逐渐显示一个大的 UIImageView。我的代码显示单一 View ，但没有动画……它只是立即显示。我想不通为什么没有几秒钟的级联效果。

newImage 是全屏图像。

imageArray 是应该翻转消失的较小图像的随机数组。

private func flipImage(newImage: UIImage, imageArray: [UIImageView]) {
    let randomImage = imageArray.first!
    let absCoordinates = randomImage.convert(self.view.frame, to: super.view)
    let absFrame = CGRect(x: absCoordinates.origin.x, y: absCoordinates.origin.y, width: randomImage.frame.width, height: randomImage.frame.height)
    if let croppedImage = newImage.cgImage?.cropping(to: absFrame) {
        let croppedImageView = UIImageView(frame: absFrame)
        croppedImageView.image = UIImage(cgImage: croppedImage)
        croppedImageView.isHidden = true
        self.view.addSubview(croppedImageView)

        let transitionOptions: UIViewAnimationOptions = [.transitionFlipFromTop, .showHideTransitionViews]
        UIView.transition(with: croppedImageView, duration: 1, options: transitionOptions, animations: {
            croppedImageView.isHidden = false
            if imageArray.count > 1 {
                var newArr = imageArray
                newArr.removeFirst()
                self.flipImage(newImage: newImage, imageArray: newArr)
            }
        })
    }
}

Answer 1

我想你想调用你的

self.flipImage(newImage: newImage, imageArray: newArr)

在完成过渡时是这样的:

UIView.transition(with: croppedImageView, duration: 1, options: transitionOptions, 
    animations: {
        croppedImageView.isHidden = false
    }, completion { _ in 
        if imageArray.count > 1 {
            var newArr = imageArray
            newArr.removeFirst()
            self.flipImage(newImage: newImage, imageArray: newArr)
        }
    }
)

这将在第一个图像完成后翻转下一个图像。

如果您不想等到转换完成，您可以在调用下一个图像翻转之前添加延迟:

UIView.transition(with: croppedImageView, duration: 1, options: transitionOptions, 
    animations: {
        croppedImageView.isHidden = false
        if imageArray.count > 1 {
            var newArr = imageArray
            newArr.removeFirst()
            self.perform(#selector(self.flip(_:)), with: [newImage, newArr], afterDelay: 0.5)
        }
    }
)

func flip(_ data: Array<Any>) {
    self.flipImage(newImage: data[0], imageArray: data[1]) // This will probably give some errors and needs some "as! Something" 
}