ios - Start playing an audio file when application goes in background -

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it's "google maps" navigate in background.

i have added "app plays audio" "required background modes" already, doesn't work. what's wrong it?

here sample source code:

-(void)applicationdidenterbackground:(uiapplication *)application { uidevice* device = [uidevice currentdevice];  bool backgroundsupported = no;  if ([device respondstoselector:@selector(ismultitaskingsupported)]) {     backgroundsupported = device.multitaskingsupported; } if (backgroundsupported && _bgtask==uibackgroundtaskinvalid ) {     uiapplication*    app = [uiapplication sharedapplication];      dispatch_async(dispatch_get_global_queue(dispatch_queue_priority_default, 0), ^{          while (app.applicationstate==uiapplicationstatebackground && _bgtask!=uibackgroundtaskinvalid)         {             [nsthread sleepfortimeinterval:3];             [self playaudio];         }          [app endbackgroundtask:_bgtask];         _bgtask = uibackgroundtaskinvalid;     }); } }  -(void)playaudio {         [[avaudiosession sharedinstance] setcategory:avaudiosessioncategoryplayback error:nil];         [[avaudiosession sharedinstance] setactive: yes error: nil];    nsurl *audiofilelocationurl = [[nsbundle mainbundle] urlforresource:@"sound" withextension:@"caf"]; nserror *error; self.audioplayer = [[avaudioplayer alloc] initwithcontentsofurl:audiofilelocationurl error:&error]; [self.audioplayer setnumberofloops:-1]; self.audioplayer.delegate = self;  [self.audioplayer preparetoplay]; [self.audioplayer play]; }

the url of audio file maybe web, , play multiple audio file in queue.

from apple's doc on subject:

because it's background tasks start in applicationdidenterbackground: not run until after method exits, should request additional background execution time before starting tasks. in other words, first call beginbackgroundtaskwithexpirationhandler: , run task on dispatch queue or secondary thread.

from own experience of playing background audio, if don't request time need set things beforehand [self.audioplayer play] literally first line of code in applicationdidenterbackground, otherwise system suspends app before audio has chance kick in , keep awake.


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