Question

我在TVos的应用中播放视频。我正在使用AVPlayerViewController播放视频。但是当我按下Apple Tv遥控器上的菜单按钮时，我会回到我来到这里的视图控制器，但是视频会继续播放，在8或10秒后它会被取消分配。这真是一个糟糕的错误，我被困在这几天。任何帮助将受到高度赞赏。

这是我的视图控制器代码。

import Foundation
import UIKit
import AVKit


class ViewController : UIViewController {


    var avplayerVC : AVPlayerViewController?
    var recentlyWatchedTimer : NSTimer?
    var lessonToWatch : Lesson?


    override func viewDidLoad() {
        super.viewDidLoad()


        if let urlVideo = lessonToWatch?.lessonurl {

            let activityIndicator = UIActivityIndicatorView(frame: CGRectMake(self.view.frame.size.width / 2.0, self.view.frame.size.height / 2.0, 30.0, 30.0))
            let asset : AVURLAsset = AVURLAsset(URL: NSURL.init(string: urlVideo)!, options: nil)
            let keys = ["playable"];
            avplayerVC = AVPlayerViewController()

            weak var weakSelf = self

            asset.loadValuesAsynchronouslyForKeys(keys) { () -> Void in
                dispatch_async(dispatch_get_main_queue(), { () -> Void in
                    weakSelf!.avplayerVC?.player =  AVPlayer(playerItem: AVPlayerItem(asset: asset))
                    weakSelf!.avplayerVC?.player?.seekToTime(kCMTimeZero)


                    print("Status 1: " +  "\(self.avplayerVC?.player?.status.rawValue)")
                    print(self.view?.frame)
                    // doesn't work

                    weakSelf!.avplayerVC?.view.frame =  self.view.frame
                    activityIndicator.stopAnimating()
                    activityIndicator.removeFromSuperview()
                    weakSelf!.view.addSubview((self.avplayerVC?.view!)!)
                    weakSelf!.avplayerVC?.player?.play()
                    weakSelf!.recentlyWatchedTimer = NSTimer.scheduledTimerWithTimeInterval(20.0, target: self, selector: "addToRecentlyWatched" , userInfo: nil, repeats: false)
                                    })
            }

            print("In LessonPlayViewController View Did Load")
            self.view.addSubview(activityIndicator)
            activityIndicator.startAnimating()
        }

    }


    func addToRecentlyWatched() {
        if let lesson = lessonToWatch {
            DataManager.sharedInstance.addRecentlyWatch(lesson)
        }
        recentlyWatchedTimer?.invalidate()
    }

    deinit {
        print("deinit")
        avplayerVC?.view.removeFromSuperview()
        avplayerVC?.player = nil
        avplayerVC = nil
    }

    // MARK : AVPlayerViewControllerDelegate


}

Answer 1

您希望在异步回调块内的所有位置使用weakSelf，但是您要一次打印self.view.frame。

Answer 2

您应该使用捕获列表来确保在闭包内对self的所有引用都是weak。然后使用guard检查引用在闭包中是否仍然有效。

import Foundation
import UIKit
import AVKit
import AVFoundation


class ViewController : UIViewController {


    var avplayerVC : AVPlayerViewController?
    var recentlyWatchedTimer : NSTimer?
    var lessonToWatch : Lesson?


    override func viewDidLoad() {
        super.viewDidLoad()


        if let urlVideo = lessonToWatch?.lessonurl {

            let activityIndicator = UIActivityIndicatorView(frame: CGRectMake(self.view.frame.size.width / 2.0, self.view.frame.size.height / 2.0, 30.0, 30.0))
            let asset : AVURLAsset = AVURLAsset(URL: NSURL.init(string: urlVideo)!, options: nil)
            let keys = ["playable"];
            avplayerVC = AVPlayerViewController()

            asset.loadValuesAsynchronouslyForKeys(keys) { [weak self] in
                dispatch_async(dispatch_get_main_queue()) { [weak self] in
                    guard let vc = self, playerVC = vc.avplayerVC else {
                        return
                    }

                    playerVC.player = AVPlayer(playerItem: AVPlayerItem(asset: asset))
                    playerVC.player?.seekToTime(kCMTimeZero)


                    print("Status 1: " +  "\(playerVC.player?.status.rawValue)")
                    print(vc.view?.frame)
                    // doesn't work

                    playerVC.view.frame = vc.view.frame
                    activityIndicator.stopAnimating()
                    activityIndicator.removeFromSuperview()
                    vc.view.addSubview(playerVC.view)
                    playerVC.player?.play()
                    vc.recentlyWatchedTimer = NSTimer.scheduledTimerWithTimeInterval(20.0, target: vc, selector: "addToRecentlyWatched" , userInfo: nil, repeats: false)
                }
            }

            print("In LessonPlayViewController View Did Load")
            self.view.addSubview(activityIndicator)
            activityIndicator.startAnimating()
        }

    }


    func addToRecentlyWatched() {
        if let lesson = lessonToWatch {
            DataManager.sharedInstance.addRecentlyWatch(lesson)
        }
        recentlyWatchedTimer?.invalidate()
    }

    deinit {
        print("deinit")
        avplayerVC?.view.removeFromSuperview()
        avplayerVC?.player = nil
        avplayerVC = nil
    }

    // MARK : AVPlayerViewControllerDelegate


}

有关捕获列表的更多信息： https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/AutomaticReferenceCounting.html#//apple_ref/doc/uid/TP40014097-CH20-ID57

修改

另请注意，在离开视图控制器时应明确停止视频播放，而不是依赖播放器停止播放作为其释放的一部分。即在viewDidDisappear或类似的。

AVPlayerViewController不立即解除分配

2 个答案: