如何监听AVPlayer的控制栏可见性变化事件？

问题说明 #

视频播放页面需全屏展示，新款带滑动手势导航的iPhone可通过手势退出页面，但iPhone 6s/7等旧机型无此功能，因此需要在AVPlayer控制栏可见时显示导航栏返回按钮，核心需求是检测AVPlayer控制栏的可见状态。

解决方案 #

由于SwiftUI原生VideoPlayer未提供控制栏可见状态的公开API，我们可以通过自定义AVPlayerViewController子类结合UIViewRepresentable来实现状态监听，具体代码如下：

1. 自定义播放器控制器子类 #

import SwiftUI
import AVKit

class CustomPlayerViewController: AVPlayerViewController {
    // 控制栏状态变化回调
    var controlsVisibilityChanged: ((Bool) -> Void)?
    
    private var autoHideTimer: Timer?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        showsPlaybackControls = true
        
        // 添加点击手势监听屏幕点击事件
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(toggleControls))
        tapGesture.cancelsTouchesInView = false
        view.addGestureRecognizer(tapGesture)
    }
    
    @objc private func toggleControls() {
        let isVisible = playbackControlsView?.alpha == 1.0
        controlsVisibilityChanged?(isVisible)
        
        // 模拟系统自动隐藏逻辑：显示控制栏后3秒无操作则隐藏
        autoHideTimer?.invalidate()
        if isVisible {
            autoHideTimer = Timer.scheduledTimer(withTimeInterval: 3.0, repeats: false) { [weak self] _ in
                self?.controlsVisibilityChanged?(false)
            }
        }
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        autoHideTimer?.invalidate()
    }
}

2. 封装为SwiftUI可用的View #

struct PlayerContainerView: UIViewRepresentable {
    let videoURL: URL
    var onControlsVisibilityChange: ((Bool) -> Void)?
    
    func makeUIView(context: Context) -> UIView {
        let containerView = UIView(frame: .zero)
        let player = AVPlayer(url: videoURL)
        let playerVC = CustomPlayerViewController()
        
        playerVC.player = player
        playerVC.controlsVisibilityChanged = onControlsVisibilityChange
        playerVC.view.frame = containerView.bounds
        playerVC.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        
        containerView.addSubview(playerVC.view)
        context.coordinator.playerVC = playerVC
        player.play()
        
        return containerView
    }
    
    func updateUIView(_ uiView: UIView, context: Context) {}
    
    func makeCoordinator() -> Coordinator {
        Coordinator()
    }
    
    class Coordinator {
        var playerVC: CustomPlayerViewController?
        
        deinit {
            playerVC?.player?.pause()
        }
    }
}

3. 改造原播放页面 #

struct VideoPlayerView: View {
    let videoURL: URL
    
    @State private var controlsAreVisible = true
    @State private var pageTitle = ""
    
    var body: some View {
        PlayerContainerView(videoURL: videoURL) { isVisible in
            DispatchQueue.main.async {
                controlsAreVisible = isVisible
            }
        }
        .edgesIgnoringSafeArea(.all)
        .navigationBarBackButtonHidden(!controlsAreVisible)
        .navigationBarHidden(!controlsAreVisible)
        .navigationBarTitle(pageTitle, displayMode: .inline)
        .statusBar(hidden: !controlsAreVisible)
        .onChange(of: controlsAreVisible) { isVisible in
            pageTitle = isVisible ? videoURL.lastPathComponent : ""
        }
    }
}

方案说明 #

• 通过自定义AVPlayerViewController，添加点击手势监听用户操作，同步控制栏可见状态到SwiftUI的状态变量。
• 用定时器模拟系统控制栏的自动隐藏逻辑，确保状态同步的准确性。
• 根据控制栏状态动态切换导航栏返回按钮、导航栏和状态栏的显示，适配旧机型的退出需求。

内容的提问来源于stack exchange，提问作者user924