How to get the count of files inside a certain folder of container in Azure Blob storage in C#

Question

I'm working with Azure Blob Storage and need to count the number of files inside a specific folder within a blob container.
I already have the prefix (example - folder1) and the container name and just need the count of the files

Is there a way without having to read all the files. I'm using dotnet 8(C#)

Should i do somthing like this or is there a proper solution

    BlobServiceClient blobServiceClient = new BlobServiceClient("DefaultEndpointsProtocol=https;AccountName=hello;AccountKey=asaACVsfFefsdsdsfadJHGDZCJSCSNyessfsfsfsfsfsc==;EndpointSuffix=core.windows.net");
    int count = 0;
    var blobContainerClient = blobServiceClient.GetBlobContainerClient("mycontainer");
    var blobs = blobContainerClient.GetBlobsAsync(prefix:"folder1");
    
    await foreach (BlobItem blob in blobs)
    {
        count++;
    }

Answer 1

How to get the count of files inside a certain folder of container in Azure Blob storage in C#

Unfortunately, Azure Blob Storage does not provide a direct API to count blobs in a folder without listing them.

The approach requires iterating through the list of blobs returned by the GetBlobsAsync method, and your approach is also correct.

Code:

using System;
using System.Threading.Tasks;
using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Models;

namespace AzureBlobStorageExample
{
    class Program
    {
        static async Task Main(string[] args)
        {
            string connectionString = "xx";
            string containerName = "result";
            string folderPrefix = "audio/";

            BlobContainerClient containerClient = new BlobContainerClient(connectionString, containerName);

            // Count the blobs in the folder
            int blobCount = await GetBlobCountAsync(containerClient, folderPrefix);

            Console.WriteLine($"Number of blobs in folder '{folderPrefix}': {blobCount}");
        }
        static async Task<int> GetBlobCountAsync(BlobContainerClient containerClient, string folderPrefix)
        {
            int count = 0;

            // Iterate through the blobs with the specified prefix
            await foreach (BlobItem blobItem in containerClient.GetBlobsAsync(prefix: folderPrefix))
            {
                count++;
            }

            return count;
        }
    }
}

Output:

Number of blobs in folder 'audio/': 3

Reference:

List blobs with .NET - Azure Storage | Microsoft Learn