关于PhotoKit获取相册

ios8之后, 获取相册就开始用PhotoKit
经过几波爬坑, 基本优化的很多

- (void)getAllAblumListFolderWithComplete:(void(^)(NSMutableArray * result))complate
{
    NSMutableArray<JYAblumList *> *photoAblumList = [NSMutableArray array];
    _photoFoldersArray = photoAblumList;
    //    dispatch_async(dispatch_get_global_queue(0, 0), ^{
    //获取所有智能相册
  
    PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAny options:nil];
    if (smartAlbums.count != 0) {
        
        [smartAlbums enumerateObjectsUsingBlock:^(PHAssetCollection * _Nonnull collection, NSUInteger idx, BOOL *stop) {
            //过滤掉视频和最近删除
            if (![collection.localizedTitle isEqualToString:@"Recently Deleted"]) {
                
                PHFetchResult* result = [PHAsset fetchKeyAssetsInAssetCollection:collection options:nil];
                if (result.firstObject) {
                    JYAblumList *ablum = [[JYAblumList alloc] init];
                    ablum.title = collection.localizedTitle;
                    ablum.count = result.count;
                    ablum.headImageAsset = result.firstObject;
                    ablum.assetCollection = collection;
                    [photoAblumList addObject:ablum];
                }
            }
            if (idx == smartAlbums.count - 1) {
                complate(photoAblumList);
            }
        }];
    }
    //获取用户创建的相册
  PHFetchOptions *options = [[PHFetchOptions alloc] init];
    options.predicate = [NSPredicate predicateWithFormat:@"estimatedAssetCount!= 0"];
    PHFetchResult *userAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAny options:options];
    if (userAlbums.count != 0) {
        [userAlbums enumerateObjectsUsingBlock:^(PHAssetCollection * _Nonnull collection, NSUInteger idx, BOOL * _Nonnull stop) {
            PHFetchResult* result = [PHAsset fetchKeyAssetsInAssetCollection:collection options:nil];
            if (result.firstObject) {
                JYAblumList *ablum = [[JYAblumList alloc] init];
                ablum.title = collection.localizedTitle;
                ablum.count = result.count;
                ablum.headImageAsset = result.firstObject;
                ablum.assetCollection = collection;
                [photoAblumList addObject:ablum];
            }

            if (idx == userAlbums.count - 1) {
                complate(photoAblumList);
            }
        }];
    }
}

划重点:
PHFetchOptions options = [[PHFetchOptions alloc] init];
options.predicate = [NSPredicate predicateWithFormat:@"estimatedAssetCount!= 0"];
这个estimatedAssetCount 在系统相册返回的值是不准确的, 在获取用户自定义相册的数量是准确的,我只是用来去掉用户自定义的空文件夹,优化整个遍历流程.
获取系统相册的准确数值
应该用
PHFetchResult result = [PHAsset fetchKeyAssetsInAssetCollection:collection options:nil];
result.count就是相册里面照片的数量
然后两个block触发事件就是会刷新两次事件,目前对我来说只能这样

接下来就是获取相应的相册的图片

/**
 按时间分照片
 
 @param assetCollection PHAssetCollection
 @param ascending BOOL
 @param complate block
 */
-(void)getAllPhotoVideoAssetDateCollection:(PHAssetCollection*) assetCollection ascending:(BOOL)ascending andComplete:(void(^)(NSMutableArray * result))complate{
    PHFetchResult *result = [self fetchAssetsInAssetCollection:assetCollection ascending:ascending];
    NSMutableArray* dateStringArray = [NSMutableArray array];
    NSMutableArray* dateModelArray = [NSMutableArray array];
    [result enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        PHAsset* asset = obj;
        if (asset.mediaType == PHAssetMediaTypeImage) {
            NSString* createDateString = [NSString stringImageDate:asset.creationDate];
            
            JSImageModel* model = [[JSImageModel alloc] init];
            model.photoAsset = asset;
            model.photoName = [[asset.localIdentifier stringByReplacingOccurrencesOfString:@"/" withString:@"__"] stringByAppendingString:@".jpg"];
            model.fileName = model.photoName;
            model.shortenFileName = model.fileName;
            model.myType = JSUploadTypePhotoAlbum;
            [self addDateModelWithDateString:createDateString toModelArray:dateModelArray withDateStringArray:dateStringArray andModel:model];
        }else if (asset.mediaType == PHAssetMediaTypeVideo){
            NSString* createDateString = [NSString stringImageDate:asset.creationDate];
            
            JSImageModel* model = [[JSImageModel alloc] init];
            PHAsset* asset = obj;
            model.photoAsset = asset;
            model.photoName = [[asset.localIdentifier stringByReplacingOccurrencesOfString:@"/" withString:@"__"] stringByAppendingString:@"AMovie.mp4"];
            model.fileName = model.photoName;
            model.shortenFileName = model.fileName;
            model.myType = JSUploadTypeVideoAlbum;
            [self addDateModelWithDateString:createDateString toModelArray:dateModelArray withDateStringArray:dateStringArray andModel:model];
        }
        
        
        if (idx == result.count - 1) {
            complate(dateModelArray);
        }
    }];
}