ios swift

Question

我正在控制页面控制，并且在每个页面中都会播放视频，但是我已经使用了xibs，在每个xib中加载每个视频，只有第一个视频正在播放，所有视频都没有播放，显示为空白屏幕。

主要代码

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    loadScrollView()
}

func loadScrollView() {
    let pageCount : CGFloat = 3.0

    scrollView.backgroundColor = UIColor.clear
    scrollView.delegate = self
    scrollView.isPagingEnabled = true
    scrollView.contentSize = CGSize(width: scrollView.frame.size.width * pageCount, height: scrollView.frame.size.height)
    scrollView.showsHorizontalScrollIndicator = false

    pageController.numberOfPages = Int(pageCount)

    let v1 = Video1.instanceFromNib() // xib with video 1
    let v2 = Video2.instanceFromNib() // xib with video 2
    let v3 = Video3.instanceFromNib() // xib with video 3

    var videoClassArray  = [v1,v2,v3] as [UIView]

    for i in 0..<Int(pageCount) {
        print(self.scrollView.frame.size.width)
        var view = UIView(frame: CGRect(x: self.scrollView.frame.size.width * CGFloat(i), y: 0, width: self.scrollView.frame.size.width, height: self.scrollView.frame.size.height))
        view = videoClassArray[i]
        self.scrollView.addSubview(view)
    }
}


//MARK: UIScrollView Delegate
func scrollViewDidScroll(_ scrollView: UIScrollView) {
    let viewWidth: CGFloat = scrollView.frame.size.width
    // content offset - tells by how much the scroll view has scrolled.
    let pageNumber = floor((scrollView.contentOffset.x - viewWidth / 50) / viewWidth) + 1
    pageController.currentPage = Int(pageNumber)
}


//MARK: Page tap action
func pageChanged() {
    let pageNumber = pageController.currentPage
    var frame = scrollView.frame
    frame.origin.x = frame.size.width * CGFloat(pageNumber)
    frame.origin.y = 0
    scrollView.scrollRectToVisible(frame, animated: true)
}

以上是视图控制器，我将xib加载到各种视图中.xib代码如下所示。

class Video1: UIView {

class func instanceFromNib() -> UIView {
    return UINib(nibName: "Video1", bundle: nil).instantiate(withOwner: nil, options: nil)[0] as! UIView
}

var player: AVPlayer!
var playerLayer = AVPlayerLayer()
var videoName = "BoardSetup_1"

@IBOutlet weak var baseView: UIView!
override init(frame: CGRect) {
     super.init(frame: frame)

}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)

}

override func layoutSubviews() {
    super.layoutSubviews()

    let videoURL = Bundle.main.url(forResource: videoName, withExtension: "mp4")

    player = AVPlayer(url: videoURL!)
    player?.actionAtItemEnd = .none
    player?.isMuted = true

    let playerLayer = AVPlayerLayer(player: player)
    playerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
    playerLayer.zPosition = -1

    playerLayer.bounds = self.layer.bounds

    playerLayer.frame = baseView.frame
    baseView.layer.addSublayer(playerLayer)
    baseView.backgroundColor = UIColor.blue

    player?.play()


    //loop video
    NotificationCenter.default.addObserver(forName: .AVPlayerItemDidPlayToEndTime, object: player?.currentItem, queue: nil, using: { (_) in
        DispatchQueue.main.async {
            self.player?.seek(to: kCMTimeZero)
            self.player.play()
        }
    })


}
}

以上代码适用于加载视频的xib，其余xib的代码相同，因此仅提及1个xib。 加载xib时面临的问题只有视频会在第一个视图中播放，在休息视图中显示为空白屏幕。

Answer 1

为什么不使用UIPageViewController进行分页？可以使用UIScrollView，但是你需要自己实现页面回收，否则你最终会浪费大量内存。