使用MusicKit ApplicationMusicPlayer播放大音乐集合时遇远程调用超时错误

方案1：分批初始化队列并追加 #

一次性传入大量QueueEntry会触发远程调用超时，可先初始化小批量基础队列，再分批追加剩余歌曲：

typealias QueueEntry = ApplicationMusicPlayer.Queue.Entry

let player = ApplicationMusicPlayer.shared
let entries: [QueueEntry] = tracks.compactMap {
    guard let song = $0 as? Song else { return nil }
    return QueueEntry(song)
}

Task(priority: .high) { [player] in
    do {
        // 先初始化前200首作为基础队列
        let initialBatch = Array(entries.prefix(200))
        player.queue = .init(initialBatch, startingAt: nil)
        
        // 分批追加剩余歌曲，每批100首，追加后短暂等待避免服务过载
        let remaining = Array(entries.dropFirst(200))
        for batch in remaining.chunked(into: 100) {
            player.queue.append(batch)
            try await Task.sleep(nanoseconds: 50_000_000) // 等待50ms
        }
        
        try await player.play()
    } catch {
        print(error)
    }
}

// 给Array添加分块扩展
extension Array {
    func chunked(into size: Int) -> [[Element]] {
        return stride(from: 0, to: count, by: size).map {
            Array(self[$0..<Swift.min($0 + size, count)])
        }
    }
}

方案2：MPMusicPlayerController分批处理播放参数 #

改用MPMusicPlayerController时，同样通过分批设置队列+追加的方式规避超时：

let player = MPMusicPlayerController.systemMusicPlayer
let playParams: [MPMusicPlayerPlayParameters] = tracks.compactMap {
    guard let song = $0 as? Song, let id = song.id else { return nil }
    return MPMusicPlayerPlayParameters(identifier: id.rawValue, kind: .song)
}

Task(priority: .high) { [player] in
    do {
        let initialBatch = Array(playParams.prefix(200))
        player.setQueue(with: initialBatch)
        
        let remaining = Array(playParams.dropFirst(200))
        for batch in remaining.chunked(into: 100) {
            player.append(batch)
            try await Task.sleep(nanoseconds: 50_000_000)
        }
        
        player.play()
    } catch {
        print(error)
    }
}

方案3：优先播放首歌+后台追加队列 #

如果需要立即响应用户播放操作，可先初始化仅含第一首歌的队列，再在后台分批追加剩余内容：

Task(priority: .high) { [player] in
    do {
        guard let firstEntry = entries.first else { return }
        // 先初始化仅含第一首的队列，立即播放
        player.queue = .init([firstEntry], startingAt: firstEntry)
        try await player.play()
        
        // 后台分批追加剩余歌曲
        let remainingEntries = Array(entries.dropFirst())
        for batch in remainingEntries.chunked(into: 100) {
            player.queue.append(batch)
            try await Task.sleep(nanoseconds: 50_000_000)
        }
    } catch {
        print(error)
    }
}

核心原因说明 #

MPMusicPlayerControllerErrorDomain Code=9本质是MusicKit远程服务处理大量请求超时，分批操作能减少单次请求的数据量，从根源避免超时触发。分块大小建议在100-200之间，间隔时间可根据设备性能微调，50-100ms即可，完全不影响自定义排序的需求。

内容的提问来源于stack exchange，提问作者Adam