Question

我正在使用以下代码在我的Swift应用程序（iOS 9）中播放视频：

        let fileUrl = NSBundle.mainBundle().URLForResource("welcome", withExtension: ".mp4")
        videoItem =  AVPlayerItem(URL: fileUrl!)
        videoPlayer = AVPlayer(playerItem: videoItem)
        videoPlayer.addObserver(self, forKeyPath: "rate", options: [.New], context: nil)

        videoPlayerController.player = videoPlayer
        videoPlayerController.showsPlaybackControls = false

        videoPlayerController.view.frame = CGRectMake(0, 0, playerView.frame.size.width, playerView.frame.size.height)
        playerView.insertSubview(videoPlayerController.view, belowSubview: videoCoverView)

        videoPlayerController.willMoveToParentViewController(self)
        addChildViewController(videoPlayerController)
        videoPlayerController.didMoveToParentViewController(self)

        playerView.bringSubviewToFront(btnPlay)

        let asset = AVAsset(URL: fileUrl!)
        let imageGenerator = AVAssetImageGenerator(asset: asset)
        let time = CMTime(seconds: asset.duration.seconds/2.0, preferredTimescale: 1)

        do {
            let imageRef = try imageGenerator.copyCGImageAtTime(time, actualTime: nil)
            let coverImage = UIImage(CGImage: imageRef)
            videoCoverView.image = coverImage
        } catch {

        }

videoPlayerController是AVPlayerViewController的一个实例。通过情节提要添加playerView并在其上设置了Autolayout。一旦AVPlayerViewController的播放器控件出现，当我尝试通过播放器控件进入全屏模式时，我将面临Autloayout问题。这是打印的日志。

2016-05-07 15:18:19.325 VoxTrain[2085:66307] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. 
    Try this: 
        (1) look at each constraint and try to figure out which you don't expect; 
        (2) find the code that added the unwanted constraint or constraints and fix it. 
    (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSAutoresizingMaskLayoutConstraint:0x7fb6a2a3f2c0 h=-&- v=-&- _UIBackdropContentView:0x7fb6a2a02310.width == _UIBackdropView:0x7fb6a053bf90.width>",
    "<NSLayoutConstraint:0x7fb6a2992800 H:|-(14)-[UILabel:0x7fb6a2991220'Hi-Speed Scrubbing']   (Names: '|':_UIBackdropContentView:0x7fb6a2a02310 )>",
    "<NSLayoutConstraint:0x7fb6a2992850 H:[UILabel:0x7fb6a2991220'Hi-Speed Scrubbing']-(14)-|   (Names: '|':_UIBackdropContentView:0x7fb6a2a02310 )>",
    "<NSLayoutConstraint:0x7fb6a29649a0 H:|-(0)-[_UIBackdropView:0x7fb6a053bf90]   (Names: '|':UIView:0x7fb6a0549220 )>",
    "<NSLayoutConstraint:0x7fb6a298b8a0 H:[_UIBackdropView:0x7fb6a053bf90]-(0)-|   (Names: '|':UIView:0x7fb6a0549220 )>",
    "<NSLayoutConstraint:0x7fb6a296f440 H:|-(0)-[UIView:0x7fb6a0549220]   (Names: '|':AVAlphaUpdatingView:0x7fb6a053dae0 )>",
    "<NSLayoutConstraint:0x7fb6a296f490 H:[UIView:0x7fb6a0549220]-(0)-|   (Names: '|':AVAlphaUpdatingView:0x7fb6a053dae0 )>",
    "<NSLayoutConstraint:0x7fb6a2a40cc0 'UIView-Encapsulated-Layout-Width' H:[AVAlphaUpdatingView:0x7fb6a053dae0(0)]>"
)

在初始方法之后，我尝试在autolayout视图上设置videoPlayerController's并将translatesAutoresizingMaskIntoConstraints设置为false。但问题仍然存在。我该如何解决这些问题？

Answer 1

使用此代码，

viewDidLoad方法：

        let type : String! = "mp4"
        let targetURL : String? = NSBundle.mainBundle().pathForResource("Welcome", ofType: type)

        let videoURL = NSURL(fileURLWithPath:targetURL!)


        let player = AVPlayer(URL: videoURL)
        let playerController = AVPlayerViewController()

        playerController.player = player
        self.addChildViewController(playerController)
        self.playView.addSubview(playerController.view)
        playerController.view.frame = playView.bounds

        player.play()

我的故事板视图在下面给出，

我创建了UIView，然后设置了解决的顶部，左侧，右侧和高度。它为我工作

希望它有用

Answer 2

问题是当您的AVPlayerController在屏幕上时，您尝试设置showsPlaybackControls = true。这样做会创建系统UI元素，从而导致自动布局问题。

Docs对这一点非常具体：

请勿使用此属性更改播放的可见性播放器视图控制器在屏幕上时控制，因为这样做所以创建或破坏UI元素。

链接： https://developer.apple.com/library/ios/documentation/AVFoundation/Reference/AVPlayerViewController_Class/#//apple_ref/occ/instp/AVPlayerViewController/showsPlaybackControls

AVPlayerController：全屏Autolayout问题

2 个答案: