PHPhotoLibrary获取相册名称

Question

我一直试图在iOS 8中用Photos获得相册名称的替代方法。在ALAssets中，我们可以使用：valueForProperty:ALAssetsGroupPropertyName，但是对于Photos，我似乎找不到替代的方法。有：localizedTitle在PHAssetCollection下，但这也不对，它只是给了我城市的名字。我正在寻找能够返回组的实际名称的东西，包括那些与iTunes同步的名称。

如果您能在您的应用程序中提供帮助，我将不胜感激。苹果鼓励我们只对与8.0链接的应用程序使用Photos，所以我不想同时使用ALAssetLibrary和Photos。

代码：

- (NSString *)nameForAlbumInCollection:(id)collection
{
    NSString *title = nil;

    if ([PHAsset class])
    {
        title = [collection localizedTitle];
    }
    else
    {
        title = [collection valueForProperty:ALAssetsGroupPropertyName];
    }

    return title;
}

- (void)setup
{
    self.recentsCollectionDataSource = [[NSMutableOrderedSet alloc]init];
    self.favoritesCollectionDataSource = [[NSMutableOrderedSet alloc]init];
    self.albumsTableDataSource = [[NSMutableOrderedSet alloc]init];

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

    self.assetsFetchResult = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum | PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAny options:nil];

    if (!self.parentController.canTakeOrChooseVideo)
    {
        fetchOptions.predicate = [NSPredicate predicateWithFormat:@"mediaType = %i",PHAssetMediaTypeImage];
    }

    for (PHAssetCollection *sub in self.assetsFetchResult)
    {
        PHFetchResult *assetsInCollection = [PHAsset fetchAssetsInAssetCollection:sub options:nil];

        for (PHAsset *asset in assetsInCollection)
        {
            NSLog(@"%@",[self nameForAlbumInCollection:sub]);

            [self.recentsCollectionDataSource addObject:asset];

            if (![segmentTitles containsObject:@"Recents"])
            {
                [segmentTitles addObject:@"Recents"];
                [segmentTitles addObject:@"Albums"];
            }

            if (asset.isFavorite)
            {
                [self.favoritesCollectionDataSource addObject:asset];

                if (![segmentTitles containsObject:@"Favorites"])
                {
                    [segmentTitles addObject:@"Favorites"];
                }
            }
        }
    }
}

Answer 1

这就是我是如何在我的一个项目中列出专辑名称的。你可能不得不偏离一点，但这应该是可行的。

NSArray *collectionsFetchResults;
NSMutableArray *localizedTitles = [[NSMutableArray alloc] init];

PHFetchResult *smartAlbums = [PHAssetCollection       fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum
                                                                      subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
PHFetchResult *syncedAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum
                                                                subtype:PHAssetCollectionSubtypeAlbumSyncedAlbum options:nil];
PHFetchResult *userCollections = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];

// Add each PHFetchResult to the array
collectionsFetchResults = @[smartAlbums, userCollections, syncedAlbums];

for (int i = 0; i < collectionsFetchResults.count; i ++) {

    PHFetchResult *fetchResult = collectionsFetchResults[i];

    for (int x = 0; x < fetchResult.count; x ++) {

        PHCollection *collection = fetchResult[x];
        localizedTitles[x] = collection.localizedTitle;

    }
}

Answer 2

我认为您可能使用的是PHCollectionList的PHCollectionList属性。正如您在问题中提到的那样，您应该在localizedTitle下使用PHAssetCollection。

我编写了一个小实用程序类，并向它添加了以下方法以检索相册名称。

+ (NSString *)localizedTitleForGroupOrCollection:(id)collection {
    NSString *title = nil;
    if ([PHAsset class]) {
        title = [collection localizedTitle];
    } else {
        title = [collection valueForProperty:ALAssetsGroupPropertyName];
    }

    return title;
}

Answer 3

位掩码不能作为PHAssetCollectionTypeAlbum、PHAssetCollectionTypeSmartAlbum和PHAssetCollectionTypeMoment指定为位字段。它们取值1，2，3。要使位掩码工作，它们必须取值1、2、4，每个值位于不同的位上。