iOS PhotoKit获取所有相册名称

//由于此方法为同步方法 所以需要放在子线程中去执行 例如:
dispatch_async(dispatch_get_global_queue(0, 0), ^{
NSMutableArray *arr = [self getAllPhoto];
NSLog(@"完成%@ \n照片总数%ld", arr, arr.count);
});

- (NSMutableArray *)getAllPhoto{
NSMutableArray *arr = [NSMutableArray array];
// 所有智能相册
PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
for (NSInteger i = 0; i < smartAlbums.count; i++) {
PHCollection *collection = smartAlbums[i];
//遍历获取相册
if ([collection isKindOfClass:[PHAssetCollection class]]) {
PHAssetCollection *assetCollection = (PHAssetCollection *)collection;
PHFetchResult *fetchResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:nil];
PHAsset *asset = nil;
if (fetchResult.count != 0) {
for (NSInteger j = 0; j < fetchResult.count; j++) {
//从相册中取出照片
asset = fetchResult[j];
PHImageRequestOptions *opt = [[PHImageRequestOptions alloc]init];
opt.synchronous = YES;
PHImageManager *imageManager = [[PHImageManager alloc] init];
[imageManager requestImageForAsset:asset targetSize:PHImageManagerMaximumSize contentMode:PHImageContentModeAspectFill options:opt resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
if (result) {
[arr addObject:result];
}
}];
}
}
}
}

//返回所有照片
return arr;
}