ios - How to scan all bar codes of type AVMetadataObjectTypeEAN13Code -

my scanner can scan barcode.

but not barcode.

this code i'm using.

#pragma mark - ibaction method implementation  - (void)startstopreading {     if (!_isreading) {         // case app should read qr code when start button tapped.         if ([self startreading]) {             // if startreading methods returns yes , capture session             // running, change start button title , status message.             [_decodedlabel settext:@"scanning qr code..."];         }     }     else{         // in case app reading qr code , should stop doing so.         [self stopreading];         // bar button item's title should change again.     }      // set flag exact opposite value of 1 has.     _isreading = !_isreading; }   #pragma mark - private method implementation  - (bool)startreading {     nserror *error;      // instance of avcapturedevice class initialize device object , provide video     // media type parameter.     avcapturedevice *capturedevice = [avcapturedevice defaultdevicewithmediatype:avmediatypevideo];      // instance of avcapturedeviceinput class using previous device object.     avcapturedeviceinput *input = [avcapturedeviceinput deviceinputwithdevice:capturedevice error:&error];      if (!input) {         // if error occurs, log description of , don't continue more.         nslog(@"%@", [error localizeddescription]);         return no;     }      // initialize capturesession object.     _capturesession = [[avcapturesession alloc] init];     // set input device on capture session.     [_capturesession addinput:input];       // initialize avcapturemetadataoutput object , set output device capture session.     avcapturemetadataoutput *capturemetadataoutput = [[avcapturemetadataoutput alloc] init];     [_capturesession addoutput:capturemetadataoutput];      // create new serial dispatch queue.     dispatch_queue_t dispatchqueue;     dispatchqueue = dispatch_queue_create("myqueue", null);     [capturemetadataoutput setmetadataobjectsdelegate:self queue:dispatchqueue];     [capturemetadataoutput setmetadataobjecttypes:[nsarray arraywithobject:avmetadataobjecttypeean13code]];      // initialize video preview layer , add sublayer viewpreview view's layer.     _videopreviewlayer = [[avcapturevideopreviewlayer alloc] initwithsession:_capturesession];     [_videopreviewlayer setvideogravity:avlayervideogravityresizeaspectfill];     [_videopreviewlayer setframe:_viewpreview.layer.bounds];     [_viewpreview.layer addsublayer:_videopreviewlayer];      // start video capture.     [_capturesession startrunning];      return yes; }   -(void)stopreading{     // stop video capture , make capture session object nil.     [_capturesession stoprunning];     _capturesession = nil;      // remove video preview layer viewpreview view's layer.     [_videopreviewlayer removefromsuperlayer]; }  #pragma mark - avcapturemetadataoutputobjectsdelegate method implementation  -(void)captureoutput:(avcaptureoutput *)captureoutput didoutputmetadataobjects:(nsarray *)metadataobjects fromconnection:(avcaptureconnection *)connection{      // check if metadataobjects array not nil , contains @ least 1 object.     if (metadataobjects != nil && [metadataobjects count] > 0) {         // metadata object.         avmetadatamachinereadablecodeobject *metadataobj = [metadataobjects objectatindex:0];         if ([[metadataobj type] isequaltostring:avmetadataobjecttypeean13code]) {             // if found metadata equal qr code metadata update status label's text,             // stop reading , change bar button item's title , flag's value.             // done on main thread.             [_decodedlabel performselectoronmainthread:@selector(settext:) withobject:[metadataobj stringvalue] waituntildone:no];              [self performselectoronmainthread:@selector(stopreading) withobject:nil waituntildone:no];             _isreading = no;             [self barcodereadgotonextpage:[metadataobj stringvalue]];              // if audio player not nil, play sound effect.             if (_audioplayer) {                 [_audioplayer play];             }         }     } } 

how can work barcodes of type avmetadataobjecttypeean13code