我正在使用PHPhotoLibrary检索多个这样的照片集:_smartAlbumsFetchResult=[PHAssetCollectionfetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbumsubtype:PHAssetCollectionSubtypeAlbumMyPhotoStreamoptions:nil];[_smartAlbumsFetchResultenumerateObjectsUsingBlock:^(PHAssetCollection*collection,NSUIntegeridx,BOOL