ios - MPMusicPlayerControllerPlaybackStateDidChangeNotification 在后台

Question

每当我播放轨道然后移至后台时，我都无法在我的应用程序中触发这些通知。有谁知道为什么或如何？

        self.player = [MPMusicPlayerController applicationMusicPlayer];
        [self.player beginGeneratingPlaybackNotifications];


        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handlePlaybackStateChanged:) name:MPMusicPlayerControllerPlaybackStateDidChangeNotification object:self.player ];


        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleItemChanged:) name:MPMusicPlayerControllerNowPlayingItemDidChangeNotification object:self.player ];

Answer 1

添加以下代码

UIBackgroundTaskIdentifier bgTask = 0;
UIApplication  *app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
    [app endBackgroundTask:bgTask];
}];

在您的 AppDelegate 的 applicationDidEnterBackground 方法中，那么您的方法也将在 BackGround 中工作。

同时启用

Audio, Airplay and Picture in Picture

来自能力。看截图