如何从自定义视图过渡到 AVPlayerViewController？答案

【问题标题】：How to transition to AVPlayerViewController from a custom view?如何从自定义视图过渡到 AVPlayerViewController？
【发布时间】：2018-05-17 00:00:53
【问题描述】：

我有一个自定义视图：

class MediaPlayerView: UIView {

    var mediaURL: URL? {
        didSet {
            determineMediaType()
        }
    }
    let videoExtensions = ["mov"]

    override init (frame : CGRect) {
        super.init(frame : frame)
    }

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

    func determineMediaType() {
        let url = self.mediaURL
        let pathExtention = url?.pathExtension
        if videoExtensions.contains(pathExtention!) {
            print("Movie URL: \(String(describing: url))")
            setupVideo(url: url!)
        } else {
            print("Image URL: \(String(describing: url))")
            setupImage(url: url!)
        }
    }

    func setupVideo(url: URL) {
        let playButton = UIImage(named: "Play Triangle")
        let playButtonView = UIImageView(image: playButton!)
        let singleTap = UITapGestureRecognizer(target: self,  action: #selector(tapDetected))
        playButtonView.addGestureRecognizer(singleTap)
        playButtonView.center = self.center
        playButtonView.frame.size.width  = self.frame.size.width/5
        playButtonView.frame.size.height = self.frame.size.height/5
        playButtonView.autoresizingMask = [.flexibleWidth,.flexibleHeight]
        playButtonView.isUserInteractionEnabled = true
        self.addSubview(playButtonView)
    }

    @objc func tapDetected() {
        print("tap!")

        let player = AVPlayer(url: self.mediaURL!)
        let controller = AVPlayerViewController()
        controller.player = player
        self.window?.rootViewController?.present(controller, animated: true) {
            player.play()
        }
    }

    func setupImage(url: URL) {
        let imageView = UIImageView()
        imageView.frame = self.bounds
        imageView.autoresizingMask = [.flexibleWidth,.flexibleHeight]
        self.addSubview(imageView)
        imageView.kf.setImage(with: url)
    }

}

但是当我点击播放按钮时，我收到以下错误：

Warning: Attempt to present <AVPlayerViewController: 0x7fe8b200b000> on <SweatNet.MainTabBarController: 0x7fe8b4816400> whose view is not in the window hierarchy!

它出现在这一行：self.window?.rootViewController?.present。我认为我调用 rootViewController（这似乎是 SweatNet.MainTabBarController）让我感到困惑。我想让它调用 SweatNet.TagViewController。这是包含包含自定义 MediaPlayerView 的单元格的单元格，但我不明白如何获取对此的引用。

【问题讨论】：

标签： ios swift avfoundation avplayer avplayerviewcontroller

【解决方案1】：

试试这个：

class func topViewController(controller: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
    if let navigationController = controller as? UINavigationController {
        return topViewController(controller: navigationController.visibleViewController)
    }
    if let tabController = controller as? UITabBarController {
        if let selected = tabController.selectedViewController {
            return topViewController(controller: selected)
        }
    }
    if let presented = controller?.presentedViewController {
        return topViewController(controller: presented)
    }
    return controller
}

把你的方法写成：

@objc func tapDetected() {
    print("tap!")

    let player = AVPlayer(url: self.mediaURL!)
    let controller = AVPlayerViewController()
    controller.player = player
    topViewController().present(controller, animated: true) {
        player.play()
    }
}

这将返回层次结构中的顶级 vc。希望对您有所帮助！

【讨论】：

【解决方案2】：

我会对此答案的一些反馈感兴趣，因为我认为这是我以错误方式思考 iOS 系统的一个例子。我最终意识到我试图将视图控制器代码放在自定义视图中。视图控制器代码是启动 AVPlayerViewController 的代码。相反，我应该把这个逻辑放在我的视图控制器中。

我所做的工作是在视图控制器内部使用 collectionView 委托方法 didSelectItemAt indexPath: IndexPath，其中集合视图的视图控制器逻辑如下所示：

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    if collectionView == self.collectionView {
        let post = posts[indexPath.row]
        if post.isVideo == true {
            self.performSegue(withIdentifier: "playVideo", sender: nil)
        } else {
            print("is image. might go full screen one day here")
        }
}

这很有效，我相信它比编写视图的自定义方面来启动 AVPlayerViewController 更好。但也有可能这两种方法都有效——我对 iOS 开发的了解还不够多，无法做出这样的决定。欢迎任何cmets。

【讨论】：