ios - AVAudioplayer not working when app is in background -

i developing app plays recordings depending on user position. having problems when trying use app in background. have enabled background modes play audio in background , working nice in simulator. problem when autoplayrecord method called app in background doesn't play record. here code:

- (void) autoplayrecord {     autoplayingrecord = [_autoplaylist objectatindex:0];      dispatch_async(dispatch_get_global_queue(dispatch_queue_priority_background, 0), ^{      loadingsong = yes;      dispatch_async(dispatch_get_main_queue(), ^{         [self showtitle:autoplayingrecord.title];         [audioplayer stop];          //make sure system follows our playback status         [[avaudiosession sharedinstance] setcategory:avaudiosessioncategoryplayback error:nil];         [[avaudiosession sharedinstance] setactive: yes error: nil];          [[uiapplication sharedapplication] beginreceivingremotecontrolevents];         [self becomefirstresponder];     });      nserror *error;     nsdata *songfile = [[nsdata alloc] initwithcontentsofurl:[nsurl urlwithstring:autoplayingrecord.audiourl] options:nsdatareadingmappedifsafe error:&error];     audioplayer = [[avaudioplayer alloc] initwithdata:songfile error:&error];     [audioplayer setdelegate:self];     [audioplayer preparetoplay];      loadingsong = no;      if (audioplayer == nil)     {         dispatch_async(dispatch_get_main_queue(), ^{             [activityindicatorview stopanimating];             [self stoprecord];         });     }     else     {         dispatch_async(dispatch_get_main_queue(), ^{             [activityindicatorview stopanimating];             [audioplayer play];         });     }     }); }