如何在 Mac (Swift) 上获取当前正在播放的歌曲

Question

在 Mac 上，触摸栏可以自动检测正在播放音频的应用程序，并让您播放/暂停、跳过甚至搜索音频。这适用于 Spotify、Quicktime 甚至浏览器中的网站，例如 Google Chrome 上的 YouTube 标签。如何使用 Swift 获取相同的信息（歌曲名称、缩略图、正在播放歌曲的应用程序、持续时间等）？

Answer 1

macOS 与媒体播放器有更多系统集成。例如，您可以向 Siri 询问当前歌曲或使用 Now Playing Today 小部件：

所有这些集成都使用 Media Remote 私有框架中的私有 API。由于它是一个私有框架，如果您尝试在 Mac App Store 上提交它，Apple 将拒绝您的应用程序。您仍然可以对其进行公证以在 App Store 之外分发。

要使用该框架，您可以尝试以下操作：

// Load framework
let bundle = CFBundleCreate(kCFAllocatorDefault, NSURL(fileURLWithPath: "/System/Library/PrivateFrameworks/MediaRemote.framework"))

// Get a Swift function for MRMediaRemoteGetNowPlayingInfo
guard let MRMediaRemoteGetNowPlayingInfoPointer = CFBundleGetFunctionPointerForName(bundle, "MRMediaRemoteGetNowPlayingInfo" as CFString) else { return }
typealias MRMediaRemoteGetNowPlayingInfoFunction = @convention(c) (DispatchQueue, @escaping ([String: Any]) -> Void) -> Void
let MRMediaRemoteGetNowPlayingInfo = unsafeBitCast(MRMediaRemoteGetNowPlayingInfoPointer, to: MRMediaRemoteGetNowPlayingInfoFunction.self)

// Get a Swift function for MRNowPlayingClientGetBundleIdentifier
guard let MRNowPlayingClientGetBundleIdentifierPointer = CFBundleGetFunctionPointerForName(bundle, "MRNowPlayingClientGetBundleIdentifier" as CFString) else { return }
typealias MRNowPlayingClientGetBundleIdentifierFunction = @convention(c) (AnyObject?) -> String
let MRNowPlayingClientGetBundleIdentifier = unsafeBitCast(MRNowPlayingClientGetBundleIdentifierPointer, to: MRNowPlayingClientGetBundleIdentifierFunction.self)

// Get song info
MRMediaRemoteGetNowPlayingInfo(DispatchQueue.main, { (information) in
    NSLog("%@", information["kMRMediaRemoteNowPlayingInfoArtist"] as! String)
    NSLog("%@", information["kMRMediaRemoteNowPlayingInfoTitle"] as! String)
    NSLog("%@", information["kMRMediaRemoteNowPlayingInfoAlbum"] as! String)
    NSLog("%@", information["kMRMediaRemoteNowPlayingInfoDuration"] as! String)
    let artwork = NSImage(data: information["kMRMediaRemoteNowPlayingInfoArtworkData"] as! Data)

    // Get bundle identifier
    let _MRNowPlayingClientProtobuf: AnyClass? = NSClassFromString("_MRNowPlayingClientProtobuf")
    let handle : UnsafeMutableRawPointer! = dlopen("/usr/lib/libobjc.A.dylib", RTLD_NOW)
    let object = unsafeBitCast(dlsym(handle, "objc_msgSend"), to:(@convention(c)(AnyClass?,Selector?)->AnyObject).self)(_MRNowPlayingClientProtobuf,Selector("a"+"lloc"))
    unsafeBitCast(dlsym(handle, "objc_msgSend"), to:(@convention(c)(AnyObject?,Selector?,Any?)->Void).self)(object,Selector("i"+"nitWithData:"),information["kMRMediaRemoteNowPlayingInfoClientPropertiesData"] as AnyObject?)
    NSLog("%@", MRNowPlayingClientGetBundleIdentifier(object))
    dlclose(handle)
})

我假设缩略图是指专辑封面。Spotify、QuickTime 和 Google Chrome，因为您提到了它们，所以不会与该私有 API 共享专辑插图。