"advanceToNextItem()" 不允许循环播放所有视频

Question

我在 KVO 的基础上获得了具有循环行为的自动播放视频片段序列。但是，除了自动播放之外，我还想使用 NSButton 推进所有剪辑。因此，如果我在序列自动播放时按下 Next Video 按钮，此操作会将我推进到队列中的下一个剪辑。但它并没有以正确的方式工作。

问题是：当队列结束时，队列中的所有剪辑都没有循环。只有第一个剪辑有一个循环（如果我按 Next Video 按钮 10 次 – 只有第一个剪辑 循环 10 次），之后所有剪辑都会正常自动播放。

问题：如何（在前进时）使用 NSButton 循环播放所有视频？

这是我的代码：

import Cocoa
import AVFoundation
import AVKit

class ViewController: NSViewController {

    @IBOutlet weak var avPlayerView: AVPlayerView!
    @IBOutlet weak var nextVideoButton: NSButton!
    @objc private let player = AVQueuePlayer()
    let clips = ["One", "Two", "Three", "Four"]
    private var token: NSKeyValueObservation?

    override func viewDidAppear() {
        super.viewDidAppear()
        addAllVideosToPlayer()
    }

    func addAllVideosToPlayer() {
        avPlayerView.player = player
        for clip in clips {
            let urlPath = Bundle.main.path(forResource: clip, ofType: "mov")!
            let url = URL(fileURLWithPath: urlPath)
            let playerItem = AVPlayerItem(url: url)
            player.insert(playerItem, after: player.items().last)

            token = player.observe(\.currentItem) { [weak self] player, _ in
                if self!.player.items().count == 1 { self?.addAllVideosToPlayer() }
            }
            player.play()
            avPlayerView.controlsStyle = .none
        }
    }

    @IBAction func nextVideo(_ sender: Any) {
        var number: Int = 0
        let clip = clips[number]

        let urlPath = Bundle.main.path(forResource: clip, ofType: "mov")!
        let url = URL(fileURLWithPath: urlPath)
        let playerItem = AVPlayerItem(url: url)
        player.insert(playerItem, after: player.items().last)

        player.advanceToNextItem()
        number += 1

        if number >= clips.count {
            number = 0
            player.advanceToNextItem()
            number += 1
        }
    }
}

这是我的 ViewController:

Answer 1

您总是在这里访问第一个视频：

  var number: Int = 0
  let clip = clips[number]

数字始终为零。将其保留为 class 的成员并在需要时更新它。

Answer 2

这是我的问题的解决方案（感谢@giorashc）：

class ViewController: NSViewController {

    var number: Int = 0                                         // class member

    .........................................
    .........................................

    @IBAction func nextVideo(_ sender: Any) {

        let clip = clips[number % 4]                            // modulus of 4   

        let urlPath = Bundle.main.path(forResource: clip, ofType: "mov")!
        let url = URL(fileURLWithPath: urlPath)
        let playerItem = AVPlayerItem(url: url)
        player.insert(playerItem, after: player.items().last)
        player.advanceToNextItem()
        number += 1
    }
}

"advanceToNextItem()" 不允许循环播放所有视频

"advanceToNextItem()" doesn't allow to loop through ALL videos

macos

avfoundation

swift

avkit

avplayerlooper