音乐播放器类程序后台运行

1.AppDelegate.m

- (void)applicationDidEnterBackground:(UIApplication *)application{    //开启后台任务，让程序保持运行状态    [application beginBackgroundTaskWithExpirationHandler:nil];}

2.info.plist

KEY: Required background modes

Item0: App plays audio or streams audio/video using AirPlay

3.设置音频回话类型

/** *  初始化 */+ (void)initialize{    _soundIDDict = [NSMutableDictionary dictionary];    _audioPlayerDict = [NSMutableDictionary dictionary];        //设置音频回话类型    AVAudioSession *session = [AVAudioSession sharedInstance];    [session setCategory:AVAudioSessionCategorySoloAmbient error:nil];    [session setActive:YES error:nil];}