How to list subdirectories in Azure blob storage

Question

MS has announced directory like blob storage, and I'm trying to use it like directories. Having save some blobs by names:

Common\Service1\Type1\Object1
Common\Service1\Type1\Object2
Common\Service1\Type2\Object1
Common\Service1\Type2\Object2
Common\Service1\Type3\Object1
Common\Service1\Type3\Object2
Common\Service1\Type3\Object3

I'd like to have possibility to enumerate subdirectories, e.g. I have blobclient referenced to Common container name, and I would like to get subcontainers list Type1, Type2, Type3. Is it possible to get list of subdirectories in some directory. Using ListBlobs returns full list of blobs within current container.

Are you talking about Blob Storage or Azure File Service? – Gaurav Mantri Nov 11 '14 at 15:05 — Gaurav Mantri, Nov 11 '14 at 15:05
@GauravMantri, Azure Blobstorage – Johnny_D Nov 11 '14 at 20:30 — Johnny_D, Nov 11 '14 at 20:30

score 19 · Accepted Answer · answered Nov 11 '14 at 15:37

If you would like to list all "subdirectories" in "Common\Service1" directory you can use something like this:

    var directory = blobContainer.GetDirectoryReference(@"Common/Service1");
    var folders = directory.ListBlobs().Where(b => b as CloudBlobDirectory != null).ToList();
    foreach (var folder in folders)
    {
        Console.WriteLine(folder.Uri);
    }

Full code sample:

    var random = new Random();
    CloudStorageAccount storageAccount = CloudStorageAccount.DevelopmentStorageAccount;
    var cloudBlobClient = storageAccount.CreateCloudBlobClient();
    CloudBlobContainer blobContainer = cloudBlobClient.GetContainerReference("test-container");
    blobContainer.CreateIfNotExists();
    string[] objects = new[]
                           {
                               @"Common\Service1\Type1\Object1", @"Common\Service1\Type1\Object2", @"Common\Service1\Type2\Object1",
                               @"Common\Service1\Type2\Object2", @"Common\Service1\Type3\Object1", @"Common\Service1\Type3\Object2",
                               @"Common\Service1\Type3\Object3"
                           };
    foreach (var newObject in objects)
    {
        var newBlob = blobContainer.GetBlockBlobReference(newObject);
        var buffer = new byte[1024];
        random.NextBytes(buffer);
        newBlob.UploadFromByteArray(buffer,0,buffer.Length);
    }

    var directory = blobContainer.GetDirectoryReference(@"Common/Service1");
    var folders = directory.ListBlobs().Where(b => b as CloudBlobDirectory != null).ToList();
    foreach (var folder in folders)
    {
        Console.WriteLine(folder.Uri);
    }

This will output Uri for Type1,Type2 and Type3 directory.

There is mistype in your code, it uses `/` instead of backslash — Johnny_D, Nov 11 '14 at 16:19
Actually it's not. I does not matter how do you get reference for blob `blobContainer.GetBlockBlobReference`, both `/` and `\ ` works, but for some reason GetDirectoryReference needs to be with `\ ` (Uri style), I guess it has something to do with directory being just a prefix and all blob prefixes are stored Uri format. — b2zw2a, Nov 11 '14 at 17:21
for me it was enough to find out there's a method like blobContainer.GetDirectoryReference(@"Common/Service1"); Thanks! — dorsz, Jun 03 '16 at 06:28

score 10 · Answer 2 · edited May 23 '17 at 10:31

Building on b2zw2a's answer:

The @ is only needed when using \, not /.
Don't chain ToList() after ListBlobs(). ListBlobs() provides lazy loading and will give you better perf.
Use OfType<CloudBlobDirectory>() to filter out only the type you want

Giving you:

var directory = blobContainer.GetDirectoryReference("Common/Service1");
var folders = directory.ListBlobs().OfType<CloudBlobDirectory>();
foreach (var folder in folders)
{
    Console.WriteLine(folder.Uri);
}

score -1 · Answer 3 · answered May 04 '17 at 13:42

-1

var nameList=logoContainer.ListBlobs().Where(b => b as CloudBlobDirectory != null).Select(x => x.Uri + "").ToList();

By using this you can get all the filenames in a single query.

answered May 04 '17 at 13:42

Pradeep Kumar Das

875
9
19

How to list subdirectories in Azure blob storage

3 Answers3