SwiftUI AVPlayer - 如何暂停和恢复播放？答案

【问题标题】：SwiftUI AVPlayer - How to pause and resume playing?SwiftUI AVPlayer - 如何暂停和恢复播放？
【发布时间】：2021-09-02 10:25:47
【问题描述】：

所以我创建了一个名为“VideoElement”的视图，它会在父视图加载时在后台播放视频。它运作良好。但是，我无法弄清楚如何实现暂停/恢复系统。我想更改一个变量（var“paused”），它会在 true 时暂停视频，在 false 时继续播放。它有点工作。具体来说，当“暂停”为真时，视频会暂停。但是，当它变为 false 时，视频不会继续播放。

也许它可能与“updateUIViewController”有关？另外，我不知道为什么“暂停”必须是绑定变量而不是状态变量（@State 不起作用）。任何帮助将不胜感激。谢谢！

import SwiftUI
import AVKit

struct VideoElement: View {

    var fileName: String
    @Binding var paused: Bool //this controls playback

    var body: some View {
    
        let player = AVPlayer(url: URL(fileURLWithPath: Bundle.main.path(forAuxiliaryExecutable: fileName)!))
    
        AVPlayerControllerRepresented(player: player)
            .onAppear {
                player.play()
            }
            .onChange(of: paused, perform: { paused in
                if paused {
                    player.pause()
                }
                else {
                    player.play() //should play the video, does not
                    print("resume") //this runs, so above should've run also
                }
            })
        }  
    }
}

struct AVPlayerControllerRepresented : UIViewControllerRepresentable {

    var player : AVPlayer

    func makeUIViewController(context: Context) -> AVPlayerViewController {
        let controller = AVPlayerViewController()
        controller.player = player
        controller.showsPlaybackControls = false
        return controller
    }

    func updateUIViewController(_ uiViewController: AVPlayerViewController, context: Context) {
    }
}

【问题讨论】：

标签： ios swiftui avplayer avplayerviewcontroller uiviewrepresentable

【解决方案1】：

我不建议在body 中创建AVPlayer——这将保证每次重新渲染视图时都会重新创建播放器。相反，将其存储在可以重新渲染的地方。我为此选择了ObservableObject。

class PlayerManager : ObservableObject {
    let player = AVPlayer(url: URL(string: "https://media.w3.org/2010/05/sintel/trailer.mp4")!)
    @Published private var playing = false
    
    func play() {
        player.play()
        playing = true
    }
    
    func playPause() {
        if playing {
            player.pause()
        } else {
            player.play()
        }
        playing.toggle()
    }
}

struct ContentView: View {
    @StateObject var playerManager = PlayerManager()
    
    var body: some View {
        VStack {
            AVPlayerControllerRepresented(player: playerManager.player)
                .onAppear {
                    playerManager.play()
                }
            Button("Play/Pause") {
                playerManager.playPause()
            }
        }
    }
}

struct AVPlayerControllerRepresented : UIViewControllerRepresentable {
    var player : AVPlayer
    
    func makeUIViewController(context: Context) -> AVPlayerViewController {
        let controller = AVPlayerViewController()
        controller.player = player
        controller.showsPlaybackControls = false
        return controller
    }
    
    func updateUIViewController(_ uiViewController: AVPlayerViewController, context: Context) {
        
    }
}

【讨论】：