在背景中播放电台

- (void)applicationDidEnterBackground:(UIApplication *)application {

    if (isAbove4_0)

 {

        CTCallCenter *_center = [[CTCallCenter alloc] init];

        _center.callEventHandler = ^(CTCall *call) 
       {

            //NSLog(@"call:%@", call.callState);
            if ([call.callState isEqualToString:CTCallStateIncoming]) 

                {

                [RadioPlayer pausePlayer];

        }           
    };
    }

}

if (isAbove4_0) {
    if (_mpmovieplayer == nil) {
        _mpmovieplayer = [[MPMoviePlayerController alloc] initWithContentURL:url];
        [_mpmovieplayer setMovieControlMode:MPMovieControlModeHidden];
    }

    [_mpmovieplayer setContentURL:url];
    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
    [[AVAudioSession sharedInstance] setActive: YES error: nil];
    // This is necessary if you want to play a sequence of songs, otherwise your app will be
    // killed after the first one finishes.
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];

    UIBackgroundTaskIdentifier newTaskId = UIBackgroundTaskInvalid;

    [_mpmovieplayer play];

    newTaskId = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:NULL];
    if (newTaskId != UIBackgroundTaskInvalid && bgTaskId != UIBackgroundTaskInvalid)
        [[UIApplication sharedApplication] endBackgroundTask: bgTaskId];
    bgTaskId = newTaskId;

}

<key>UIBackgroundModes</key>
<array>
<string>audio</string>
</array>

UIBackgroundTaskIdentifier backgroundTask = [application beginBackgroundTaskWithExpirationHandler:^{
     /* just fail if this happens. */
     NSLog(@"BackgroundTask Expiration Handler is called");
     [application endBackgroundTask:backgroundTask];
}];