ALAsset library in iOS

Question

It code is working on simulator but on device is not working and i'm not getting gallery images from device

imageArray=[[NSArray alloc] init];
name=[[NSArray alloc]init];
mutableArray =[[NSMutableArray alloc]init];

// self.title = [library valueForProperty:ALAssetsGroupPropertyName];

ALAuthorizationStatus status = [ALAssetsLibrary authorizationStatus];

NSMutableArray* assetURLDictionaries = [[NSMutableArray alloc] init];

library = [[ALAssetsLibrary alloc] init];

void (^assetEnumerator)( ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {

    NSLog(@"%zd",result);

    if(result != nil) {
        if([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]) {
            [assetURLDictionaries addObject:[result valueForProperty:ALAssetPropertyURLs]];

            NSURL *url= (NSURL*) [[result defaultRepresentation]url];

            [library assetForURL:url
                     resultBlock:^(ALAsset *asset) {
                         [mutableArray addObject:[UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]]];

                         if ([mutableArray count]==count ) {
                            // name=[[NSArray alloc]initWithArray:lisk];

                             imageArray=[[NSArray alloc] initWithArray:mutableArray];
                              _listImageArrayFromGallery=[[NSMutableArray alloc]init];

                             for (int i=0; i<imageArray.count; i++) {
                                 [_listImageArrayFromGallery addObject:[imageArray objectAtIndex:i]];
                             }

                             NSLog(@"ListPic%@",_listImageArrayFromGallery);

                             loadedCards = [[NSMutableArray alloc] init];
                             allCards = [[NSMutableArray alloc] init];
                             cardsLoadedIndex = 0;
                             [self loadCards];

                            // [self allPhotosCollected:imageArray];
                         }
                     }
                    failureBlock:^(NSError *error){ NSLog(@"operation was not successfull!"); } ];
        }
    }
};

NSMutableArray *assetGroups = [[NSMutableArray alloc] init];

void (^ assetGroupEnumerator) ( ALAssetsGroup *, BOOL *)= ^(ALAssetsGroup *group, BOOL *stop) {
    if(group != nil) {
        [group enumerateAssetsUsingBlock:assetEnumerator];
        [assetGroups addObject:group];
        count=[group numberOfAssets];
        //[assetGrpImage addObject:assetGroups];

        //assetGrpImage=[assetGrpImage valueForKey:@"Camera Roll"];
    }
};

assetGroups = [[NSMutableArray alloc] init];

[library enumerateGroupsWithTypes:ALAssetsGroupAll
                       usingBlock:assetGroupEnumerator
                     failureBlock:^(NSError *error) {NSLog(@"There is an error");}];

In this code I'm getting simulator gallery images, but on device I'm not getting gellery images.