如何使用c#获取Azure Blob存储容器中的现有目录列表?

问题描述：

我在Core .NET 2.2框架的顶部有一个使用C#编写的控制台应用程序.

I have a console app written using C# on the top of Core .NET 2.2 framework.

我正在尝试

I am trying to the C# library to get a list of all directories inside my container. It is my understanding that Azure Blob Storage does not really have directories. Instead, it creates virtual names that the blobs look like a folder inside a container within browsers like Azure Blob Explorer

我使用以下代码存储文件

I store my files using the following code

CloudBlockBlob blockBlob = container.GetBlockBlobReference("foldername/filename.jpg");

await blockBlob.UploadFromStreamAsync(stream);

所以我想在我的容器内选择一个前缀又名文件夹名称的列表.

So I want to select a distinct list of the prefix aka folder names on inside my container.

因此，如果我有以下斑点"foldername1/file1.jpg"，"foldername1/file2.jpg"，"foldername1/file3.jpg"和"foldername2/file1.jpg".我想返回"foldername1"，"foldername2"

So if I have the following blobs "foldername1/file1.jpg", "foldername1/file2.jpg", "foldername1/file3.jpg", and "foldername2/file1.jpg". I want to return "foldername1", "foldername2"

如何从Azure Blob存储中获取不同前缀的列表?

How can I get a list of distinct prefixes from Azure Blob Storage?

已更新

我试图从下面的评论中获得反馈，所以我想出了以下代码

I tried to get the feedback from the comments below so I came up with the following code

public async Task<string[]> Directories(string path = null)
{
    int index = path == null ? 0 : path.Split('/', StringSplitOptions.RemoveEmptyEntries).Length;

    BlobContinuationToken token = null;
    List<string> directories = new List<string>();
    do
    {
        BlobResultSegment blobsListingResult = await ContainerFactory.Get().ListBlobsSegmentedAsync(path ?? string.Empty, true, BlobListingDetails.None, 5000, token, null, null);
        token = blobsListingResult.ContinuationToken;
        IEnumerable<IListBlobItem> blobsList = blobsListingResult.Results;
        foreach (var item in blobsList)
        {
            var blobName = (item as CloudBlob).Name;
            var blobParts = blobName.Split('/', StringSplitOptions.RemoveEmptyEntries);

            if (blobParts.Length <= index)
            {
                // At this point, we know that this not a directory inside the provided path directory
                continue;
            }

            directories.Add(blobParts[index]);
        }
    }
    while (token != null);

    return directories.Distinct().ToArray();
}

由于容器中有很多Blob，因此花费的时间太长，因为它几乎必须获取每个块才能获取目录列表.另外，这可能会非常昂贵，因为每次调用此方法时我都必须读取每个blob.

Since I have lots of blobs in the container, this takes way too long because it would have to almost get every single block in order to get a list of the directories. Additionally, this may be very costly since I have to read every blob every time this method is called.

如果一切都在本地运行，我基本上需要与运行Directory.GetDirectories(path)相同的结果！ 是否可以改善此功能?

I essentially need the same result that I would get as running Directory.GetDirectories(path) if everything was running locally! Is there a way to improve this function?

答

也许您可以通过检查blob项的类型来改进您的解决方案?

Maybe you can improve your solution doing a check for the type of blob item?

        var result = new List<string>();
        var directory = _blobContainer.GetDirectoryReference(relativeFilePath);

        if (directory.Equals(null))
            return result;

        var blobs = directory.ListBlobsSegmentedAsync(null).Result;

        foreach (var item in blobs.Results)
        {
            if (item.GetType() == typeof(CloudBlobDirectory)) 
            {
                result.Add(item.Uri.Segments.Last().Trim('/'));
            }
        }

        return result;

我没有太多文件夹，所以最好再次检查一下性能是否符合您的要求.

I didn't have too many folders so would be good to double check if the performance meets your requirements.

如何使用c#获取Azure Blob存储容器中的现有目录列表?

相关推荐