iOS后台运行之后台播放音乐

必看参考文章：后台播放音乐

后台播放核心代码

@interface AppDelegate ()
{
    UIBackgroundTaskIdentifier _bgTaskId;
}

- (void)applicationWillResignActive:(UIApplication *)application {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    
    //开启后台处理多媒体事件
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    AVAudioSession *session=[AVAudioSession sharedInstance];
    [session setActive:YES error:nil];
    //后台播放
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];
    //这样做，可以在按home键进入后台后 ，播放一段时间，几分钟吧。但是不能持续播放网络歌曲，若需要持续播放网络歌曲，还需要申请后台任务id，具体做法是：
    _bgTaskId = [AppDelegate backgroundPlayerID:_bgTaskId];
}
//实现一下backgroundPlayerID:这个方法:
+(UIBackgroundTaskIdentifier)backgroundPlayerID:(UIBackgroundTaskIdentifier)backTaskId
{
    //设置并激活音频会话类别
    AVAudioSession *session=[AVAudioSession sharedInstance];
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];
    [session setActive:YES error:nil];
    //允许应用程序接收远程控制
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    //设置后台任务ID
    UIBackgroundTaskIdentifier newTaskId=UIBackgroundTaskInvalid;
    newTaskId=[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil];
    if(newTaskId!=UIBackgroundTaskInvalid&&backTaskId!=UIBackgroundTaskInvalid)
    {
        [[UIApplication sharedApplication] endBackgroundTask:backTaskId];
    }
    return newTaskId;
}

电话中断后继续播放核心代码

//处理中断事件的通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleInterreption:) name:AVAudioSessionInterruptionNotification object:[AVAudioSession sharedInstance]];

//处理中断事件
-(void)handleInterreption:(NSNotification *)sender
{
    [_audioStream pause];//_audioStream 是第三方FreeStream的实例变量
    
}