iOS 相册创建文件夹并对照片进行命名

一、前言

项目开发中遇到需要保存照片到特定文件夹的功能，并且图片还要自定义名称，因为平时都是直接保存使用还没有涉及过特定保存，所以这里记录下实现过程

二、相册文件夹创建和保存

-(PHAssetCollection *)getAssetCollectionAppNameAndCreate
{
    //设置你想要创建的相册的名字
    NSString *title = @"自定义相册";
    //获取与要创建的相册同名的自定义相册
    PHFetchResult *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
    for (PHAssetCollection *collection in collections) {
        //遍历
        if ([collection.localizedTitle isEqualToString:title]) {
            //找到了同名的自定义相册，返回
            return collection;
        }
    }
    //程序走到这，说明没有找到自定义的相册，需要创建
    NSError *error = nil;
    __block NSString *createID = nil; //用来获取创建好的相册
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        //发起了创建新相册的请求，并拿到相册的id，当前并没有创建成功，待创建成功后，通过id来获取创建好的自定义相册
        PHAssetCollectionChangeRequest *request = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title];
        createID = request.placeholderForCreatedAssetCollection.localIdentifier;
    } error:&error];
    if (error) {
        NSLog(@"创建失败");
        return nil;
    }else{
        NSLog(@"创建成功");
        //通过id获取创建完成的相册
        return [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[createID] options:nil].firstObject;
    }
}

-(PHFetchResult *)saveImageWithFileUrl:(NSString *)fileUrl
{
    __block NSString *createdAssetID = nil;
    NSError *error = nil;
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        //直接保存image，不可设置名称
//        createdAssetID = [PHAssetChangeRequest creationRequestForAssetFromImage:image].placeholderForCreatedAsset.localIdentifier;
        // 根据路径保存图片，可设置名称
        PHAssetCreationRequest *request = [PHAssetCreationRequest creationRequestForAsset];
        createdAssetID = request.placeholderForCreatedAsset.localIdentifier;
        PHAssetResourceCreationOptions *option = [[PHAssetResourceCreationOptions alloc] init];
        option.shouldMoveFile = YES;
        option.originalFilename = @"照片的名字啊";
        [request addResourceWithType:PHAssetResourceTypePhoto fileURL:[NSURL fileURLWithPath:fileUrl] options:option];
    } error:&error];
    if (error) {
        return nil;
    }
    //获取保存到系统相册成功后的 asset 对象集合(一张图片也是返回一个集合)
    PHFetchResult *assets = [PHAsset fetchAssetsWithLocalIdentifiers:@[createdAssetID] options:nil];
    return assets;
}

// 保存到相册
- (void)keepToAlbum {
    PHAssetCollection *assetCollection = [self getAssetCollectionAppNameAndCreate];
    if (assetCollection == nil) {
           NSLog(@"相册创建失败");
           return;
    }
    //将图片保存到系统的相册
    PHFetchResult *assets = [self saveImageWithFileUrl:self.fileUrl];
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        //选取自定义相册进行操作
        PHAssetCollectionChangeRequest *collectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
        //插入图片到自定义相册
        PHFetchResult *assetCount = [PHAsset fetchAssetsInAssetCollection:assetCollection options:nil];
        [collectionChangeRequest insertAssets:assets atIndexes:[NSIndexSet indexSetWithIndex:assetCount.count]];
        NSLog(@" 保存完成");
    } completionHandler:^(BOOL success, NSError * _Nullable error) {

    }];
}

三、相册文件夹图片读取

/// 获取文件夹
-(PHAssetCollection *)getAssetCollectionAppName {
    //设置你想要创建的相册的名字, 和保存的时候名字相同即可获取到那个文件夹
    NSString *title = @"自定义相册";
    //获取与要创建的相册同名的自定义相册
    PHFetchResult *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
    for (PHAssetCollection *collection in collections) {
        //遍历
        if ([collection.localizedTitle isEqualToString:title]) {
            //找到了同名的自定义相册，返回
            return collection;
        }
    }
    return nil;
}

// 加载图片
- (void)loadPhotoes {
    PHAssetCollection *assetCollection = [self getAssetCollectionAppName];
    if (assetCollection == nil) {
           NSLog(@"相册创建失败");
           return;
    }
    PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
    //ascending为NO，即为逆序(由现在到过去)， ascending为YES时即为默认排序，由远到近
    NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO];
    fetchOptions.sortDescriptors = @[sort];
    PHFetchResult *assetCount = [PHAsset fetchAssetsInAssetCollection:assetCollection options:fetchOptions];
    for (int i = 0; i *resources = [PHAssetResource assetResourcesForAsset:asset];
            PHAssetResource *firstResource = resources.firstObject;
          // 第二种获取照片路径的方法
            NSString *privateFileURL = [NSString stringWithFormat:@"%@",[firstResource valueForKey:@"privateFileURL"]];
            if (fileUrl.length <= 0 || [@"(null)" isEqualToString:fileUrl]) {
                fileUrl = privateFileURL;
            }
           NSString *fileName = @"未命名";
           if (firstResource){
                fileName = firstResource.originalFilename;
            }
           NSLog(@"fileName:%@", fileName);
          // 拿到了fileUrl 和 fileName，就可以根据自己的需要处理了
        }];
    }
    [self.tableView reloadData];
}

四、总结

以上是照片文件夹创建和获取的情况，有问题大家可以评论区沟通