最後に、PHFetchResult の代わりに NSArray を使用します...
//すべて取得
PHFetchOptions *allPhotosfetchOption = [[PHFetchOptions alloc]init];
allPhotosfetchOption.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
allPhotosfetchOption.predicate = [NSPredicate predicateWithFormat:@"mediaType == 1"];
__block NSMutableArray *allAssetArray = [NSMutableArray new];
PHFetchResult *result = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:allPhotosfetchOption];
[result enumerateObjectsUsingBlock:^(PHAsset *asset, NSUInteger idx, BOOL *stop) {
[allAssetArray addObject:asset];
}];
//MyCam Album
NSString *string = @"MyCam";
PHFetchOptions *albumFetchOption = [[PHFetchOptions alloc]init];
albumFetchOption.predicate = [NSPredicate predicateWithFormat:@"title == %@",string];
PHFetchResult *albumResult = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:albumFetchOption];
[albumResult enumerateObjectsUsingBlock:^(PHAssetCollection *collection, NSUInteger idx, BOOL *stop) {
PHFetchResult *loftAssetResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil];
[loftAssetResult enumerateObjectsUsingBlock:^(PHAsset *asset, NSUInteger idx, BOOL *stop) {
if ([allAssetArray containsObject:asset]) {
[allAssetArray removeObject:asset];
}
}];
}];