在 UIScrollView 中调整 AVPlayer 的大小答案

【问题标题】：Resizing AVPlayer in UIScrollView在 UIScrollView 中调整 AVPlayer 的大小
【发布时间】：2017-03-14 21:41:18
【问题描述】：

我有一个AVPlayerViewController，它的AVPlayer 视图被添加为UIView 的子视图。这个UIView 被添加到UIScrollView。这个想法是为视频实现“移动和缩放”视图。当UIScrollView 中的视图是UIImageView 时，我可以使用它。但是，当视图是带有AVPlayer 子视图的UIView 时，UIView 的比例会显得太小。

这是我的代码：

override func viewDidLoad() {
    super.viewDidLoad()

    videoPlayerController = VideoPlayerController()
    videoPlayerController.videoURL = url
    self.addChildViewController(videoPlayerController)
    videoView.addSubview(videoPlayerController.view)

    videoPlayerController.view.translatesAutoresizingMaskIntoConstraints = false

    let left = NSLayoutConstraint(item: videoPlayerController.view, attribute: .left, relatedBy: .equal, toItem: videoView, attribute: .left, multiplier: 1, constant: 0)
    let right = NSLayoutConstraint(item: videoPlayerController.view, attribute: .right, relatedBy: .equal, toItem: videoView, attribute: .right, multiplier: 1, constant: 0)
    let top = NSLayoutConstraint(item: videoPlayerController.view, attribute: .top, relatedBy: .equal, toItem: videoView, attribute: .top, multiplier: 1, constant: 0)
    let bottom = NSLayoutConstraint(item: videoPlayerController.view, attribute: .bottom, relatedBy: .equal, toItem: videoView, attribute: .bottom, multiplier: 1, constant: 0)

    videoView.addConstraints([left, right, top, bottom])

    let asset = AVAsset(url: url)
    let clipVideoTrack = asset.tracks(withMediaType: AVMediaTypeVideo).first!
    videoView.frame = CGRect(x: 0, y: 0, width: clipVideoTrack.naturalSize.height, height: clipVideoTrack.naturalSize.width)
    setZoomScale()
}

fileprivate func setZoomScale() {
    let widthScale = scrollView.bounds.size.width / videoView.bounds.size.width

    scrollView.minimumZoomScale = widthScale
    scrollView.zoomScale = widthScale
}

func viewForZooming(in scrollView: UIScrollView) -> UIView? {
    return videoView
}

func scrollViewDidZoom(_ scrollView: UIScrollView) {
    let videoViewSize = videoView.frame.size
    let scrollViewSize = scrollView.bounds.size

    let verticalPadding = videoViewSize.height < scrollViewSize.height ? (scrollViewSize.height - videoViewSize.height) / 2 : 0
    let horizontalPadding = videoViewSize.width < scrollViewSize.width ? (scrollViewSize.width - videoViewSize.width) / 2 : 0
    }

    scrollView.contentInset = UIEdgeInsets(top: verticalPadding, left: horizontalPadding, bottom: verticalPadding, right: horizontalPadding)
}

应该发生的是videoView 应该填充屏幕的宽度并居中，并能够放大到其自然大小。相反，视图在屏幕上显示为居中但小得多（可能小 3 倍）。我做错了什么？

【问题讨论】：

标签： ios swift uiscrollview

【解决方案1】：

Swift5

请试试这个，它会给你你需要的视频大小。

    let offsetX = max((scrollView.bounds.width - scrollView.contentSize.width) * 0.5, 0)
            let offsetY = max((scrollView.bounds.height - scrollView.contentSize.height) * 0.5, 0)
            scrollView.contentInset = UIEdgeInsets(top: offsetY, left: offsetX, bottom: 0, right: 0)

【讨论】：