我在 View 控制器中实现了两个功能（setupRemoteTransportControls() 和 setupNowPlaying()）并向 AppDelegate 添加了一个功能，但我仍然无法在锁定屏幕上看到我的应用程序的背景音频控件，而且音频中断功能也不是工作。这是来自 url 的实时流，您可以在代码中看到。在常规设置中，我添加了后台播放：
我想做的是在远程命令中心艺术家、标题和专辑艺术标签和 UIImage 上打印（标签 UIImage 取自我的站 API），但我只显示命令中心就卡住了。这是我的代码：
import UIKit
import AVKit
import MediaPlayer
class ViewController: UIViewController, AVAudioPlayerDelegate {
@IBAction func buttonPressed(_ sender: UIButton){
if isPlaying {
player.pause()
sender.setImage(playImage, for: .normal)
} else {
let url = "https://myradio.com/radio.mp3"
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default, options: [.mixWithOthers, .allowAirPlay])
try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playback, options: [])
print("Playback OK")
try AVAudioSession.sharedInstance().setActive(true)
print("Session is Active")
} catch {
print(error)
}
player = AVPlayer(url: URL(string: url)!)
player.volume = 1.0
player.rate = 1.0
player.play()
sender.setImage(pauseImage, for: .normal)
}
isPlaying.toggle()
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
overrideUserInterfaceStyle = .light
setupRemoteTransportControls()
requestNowPlaying()
setupNowPlaying()
}
// Here is the API data downloading part, so i skipped it
//Command Center audio controls
func setupRemoteTransportControls() {
// Get the shared MPRemoteCommandCenter
let commandCenter = MPRemoteCommandCenter.shared()
// Add handler for Play Command
commandCenter.playCommand.addTarget { [unowned self] event in
if self.player.rate == 1.0 {
self.player.play()
return .success
}
return .commandFailed
}
// Add handler for Pause Command
commandCenter.pauseCommand.addTarget { [unowned self] event in
if self.player.rate == 1.0 {
self.player.pause()
return .success
}
return .commandFailed
}
}
func setupNowPlaying() {
// Define Now Playing Info
var nowPlayingInfo = [String : Any]()
nowPlayingInfo[MPMediaItemPropertyTitle] = "Test"
if let image = UIImage(named: "Default_albumart") {
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size) { size in
return image
}
}
nowPlayingInfo[MPNowPlayingInfoPropertyIsLiveStream] = true
// Set the metadata
MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
}
func updateNowPlaying(isPause: Bool) {
// Define Now Playing Info
let nowPlayingInfo = MPNowPlayingInfoCenter.default().nowPlayingInfo!
//nowPlayingInfo[MPNowPlayingInfoPropertyElapsedPlaybackTime] = player.currentTime
//nowPlayingInfo[MPNowPlayingInfoPropertyPlaybackRate] = isPause ? 0 : 1
// Set the metadata
MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
}
//audio interruption
@objc func handleInterruption(notification: Notification) {
guard let userInfo = notification.userInfo,
let typeValue = userInfo[AVAudioSessionInterruptionTypeKey] as? UInt,
let type = AVAudioSession.InterruptionType(rawValue: typeValue) else {
return
}
// Switch over the interruption type.
switch type {
case .began:
print("Interruption began")
case .ended:
// An interruption ended. Resume playback, if appropriate.
guard let optionsValue = userInfo[AVAudioSessionInterruptionOptionKey] as? UInt else { return }
let options = AVAudioSession.InterruptionOptions(rawValue: optionsValue)
if options.contains(.shouldResume) {
player.play()
} else {
// An interruption ended. Don't resume playback.
}
default: ()
}
}
}
这是我在 My AppDelegate.swift 中添加的内容：
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
application.beginReceivingRemoteControlEvents()
// Override point for customization after application launch.
return true
}