Question

我正在开发一个播放音频文件或流的应用程序，遇到了我无法解决的问题。本质上，当前项目发生故障后，我的AVPlayer不再播放新项目。下面是一个快速的应用程序，您可以复制/粘贴以进行复制。

import UIKit
import AVFoundation

class ViewController: UIViewController {
    @objc var player: AVPlayer!
    override func viewDidLoad() {
        super.viewDidLoad()
        self.player = AVPlayer.init(playerItem: AVPlayerItem.init(url: URL.init(string: "file:///Users/bobsacamano/Library/Developer/CoreSimulator/Devices/AD4CC461-847E-441B-98BA-D5A62EE210AE/data/Containers/Data/Application/F3AEA610-5358-4EAD-93B3-F30E9491D052/Library/07E2837C-5FF2-4B30-99A7-CCE683C19C29.mp3")!))
        self.player.play()
        self.addObserver(self, forKeyPath: #keyPath(player.currentItem.status), options: .new, context: nil)
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

     override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
        if keyPath == #keyPath(player.currentItem.status) {
            switch player.currentItem!.status {
            case .readyToPlay:
                print("Ready to play")
            case .failed:
                print("Failure \(String(describing: player.currentItem!.error?.localizedDescription))")
                self.player.replaceCurrentItem(with: AVPlayerItem.init(url: URL.init(string: "http://traffic.libsyn.com/atpfm/atp281.mp3")!))
                self.player.play()
            case .unknown:
                print("Unknown")
            }
        }
    }
}

初始AVPlayerItem不存在，因此KVO将返回失败。如果我尝试用有效的URL替换该项目，则仍然无法播放。我缺少明显的东西吗？

Answer 1

https://developer.apple.com/documentation/avfoundation/avplayer/1388096-status文档说：“当此属性的值为AVPlayer.Status.failed时，您将无法再使用播放器进行播放，而需要创建一个新实例来替换它。”

发生故障后，AVPlayer将不会播放新的AVPlayerItem

1 个答案: