How to delete files from blob container?

Question

private readonly CloudBlobContainer _blobContainer;

public void Remove()
{
    if (_blobContainer.Exists())
    {
       _blobContainer.Delete();
    }
}

How to delete not a whole container but some List<string> disks that in the container?

Possible duplicate of [How to clean an Azure storage Blob container?](http://stackoverflow.com/questions/10426213/how-to-clean-an-azure-storage-blob-container) — Bushuev, Apr 08 '16 at 11:08
@h.o.m.a.n He want's to be able to delete specific blobs, not the whole thing though.. — Callum Linington, Apr 08 '16 at 12:55
@CallumLinington you can modify this code to remove some files from container like this 'Parallel.ForEach(_cloudBlobClient.GetContainerReference(nameContainer).ListBlobs(), x => { if (list.Contains(((CloudBlob)x).Name)) ((CloudBlob)x).DeleteIfExists(); });' — Bushuev, Apr 08 '16 at 13:15

score 42 · Accepted Answer · edited Oct 13 '21 at 07:07

42

This is the code I use:

private CloudBlobContainer blobContainer;

public void DeleteFile(string uniqueFileIdentifier)
{
    this.AssertBlobContainer();

    var blob = this.blobContainer.GetBlockBlobReference(uniqueFileIdentifier);
    blob.DeleteIfExists();
}

private void AssertBlobContainer()
{
    // only do once
    if (this.blobContainer == null)
    {
        lock (this.blobContainerLockObj)
        {
            if (this.blobContainer == null)
            {
                var client = this.cloudStorageAccount.CreateCloudBlobClient();

                this.blobContainer = client.GetContainerReference(this.containerName.ToLowerInvariant());

                if (!this.blobContainer.Exists())
                {
                    throw new CustomRuntimeException("Container {0} does not exist in azure account", containerName);
                }
            }
        }
    }

    if (this.blobContainer == null) throw new NullReferenceException("Blob Empty");
}

You can ignore the locking code if you know this isn't going to be accessed simultaneously

Obviously, you have the blobContainer stuff sorted, so all you need is that DeleteFile method without the this.AssertBlobContainer().

edited Oct 13 '21 at 07:07

Ellis Thompson

408
6
18

answered Apr 08 '16 at 10:34

Callum Linington

14,213
12
75
154

3

What is filename in var blob = this.blobContainer.GetBlockBlobReference(fileName);? I guess its uniqueFileIdentifier. – Syaiful Nizam Yahya Apr 03 '18 at 03:37
Good stuff, i suggest instead of calling Assert before every call, leverage singleton pattern through using a property with a backing field – Saad Alothman Apr 28 '18 at 13:22
take into account that this way you are not deleting its snapshots, just the blob itself – DanielV Nov 08 '21 at 15:11
Can you update this answer? `CloudBlobContainer` and `Microsoft.Azure.Storage` has since been deprecated. – LatentDenis Jan 21 '22 at 20:30
yeah sure - I'll do it next week - thanks for reminding me – Callum Linington Feb 18 '22 at 10:11

score 17 · Answer 2 · answered Nov 23 '20 at 10:57

17

Remember SDK v11 has been deprecated, with SDK v12:

using Azure.Storage.Blobs;
...
BlobServiceClient blobServiceClient = new BlobServiceClient("StorageConnectionString");
BlobContainerClient cont = blobServiceClient.GetBlobContainerClient("containerName");
cont.GetBlobClient("FileName.ext").DeleteIfExists();

answered Nov 23 '20 at 10:57

mainmind83

491
4
7

I get the error: The specified resource name length is not within the permissible limits – Jnr Jul 28 '21 at 17:42
@JNr this is another error: https://stackoverflow.com/questions/57328134/the-specified-resource-name-length-is-not-within-the-permissible-limits-azure-bl – mainmind83 Sep 22 '21 at 10:41

score 3 · Answer 3 · answered May 01 '20 at 13:27

There's a method called DeleteIfExistis(). Returns true/false.

CloudBlockBlob blob = CloudBlobContainer.GetBlockBlobReference(fileName);
blob.DeleteIfExists();

Filename is ContainerName/FileName, if is inside folders you need to mention the folder too. Like ContainerName/AppData/FileName and will work.

score 2 · Answer 4 · answered Mar 02 '21 at 08:55

A single line code to perform deletion

private static async Task DeleteBLOBFile(string blobNamewithFileExtension)
        {
            BlobClient blobClient = new BlobClient(blobConnectionString,containerName,blobNamewithFileExtension);
            await blobClient.DeleteIfExistsAsync();            
        }

score 1 · Answer 5 · answered Jul 24 '19 at 13:24

We can use the cloudBlobContainer.ListBlobsSegmentedAsync to list the blobs and then cast it as ICloudBlob so that you can perform the DeleteIfExistsAsync. Below is the working sample function. Hope it helps.

public async Task < bool > PerformTasks() {
    try {
        if (CloudStorageAccount.TryParse(StorageConnectionString, out CloudStorageAccount cloudStorageAccount)) {
            var cloudBlobClient = cloudStorageAccount.CreateCloudBlobClient();
            var cloudBlobContainer = cloudBlobClient.GetContainerReference(_blobContainerName);
            if (await cloudBlobContainer.ExistsAsync()) {
                BlobContinuationToken blobContinuationToken = null;
                var blobList = await cloudBlobContainer.ListBlobsSegmentedAsync(blobContinuationToken);
                var cloudBlobList = blobList.Results.Select(blb = >blb as ICloudBlob);
                foreach(var item in cloudBlobList) {
                    await item.DeleteIfExistsAsync();
                }
                return true;
            }
            else {
                _logger.LogError(ErrorMessages.NoBlobContainerAvailable);
            }
        }
        else {
            _logger.LogError(ErrorMessages.NoStorageConnectionStringAvailable);
        }
    }
    catch(Exception ex) {
        _logger.LogError(ex.Message);
    }
    return false;
}

score -1 · Answer 6 · answered May 06 '19 at 13:17

List<string> FileNameList = new List<string>();
FileNameList = fileName.Split(',').Where(t => t.ToString().Trim() != "").ToList();
CloudBlobClient client;
CloudBlobContainer container;
CloudBlockBlob blob;
string accessKey;
string accountName;
string connectionString;
accessKey = Environment.GetEnvironmentVariable("StorageAccountaccessKey");
accountName = Environment.GetEnvironmentVariable("StorageAccountName");
connectionString = Environment.GetEnvironmentVariable("StorageAccountConnectionString");
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
client = storageAccount.CreateCloudBlobClient();
string containerName = tenantId;
container = client.GetContainerReference(containerName);

foreach(var file in FileNameList)
{
   blob = container.GetBlockBlobReference(file);
   blob.DeleteIfExists();
}

This code works but it's a mess. Unused variables, bad naming, etc. Please clean it up if you are going to submit it for others. — smurtagh, Feb 17 '20 at 21:49

How to delete files from blob container?

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