Assistance Required with Tags Property Error in Azure Blob Storage Application

Question

Hello,

I am currently developing an application using Azure Blob Storage and have encountered an error related to the Tags property of the BlobInfo class. Despite the Tags property being defined in the class, I am receiving an error indicating that the property does not exist.

Error Message:
'BlobInfo' does not contain a definition for 'Tags' and no accessible extension method 'Tags' accepting a first argument of type 'BlobInfo' could be found (are you missing a using directive or an assembly reference?)

public class BlobInfo
{
    public string ImageUri { get; set; }
    public string ThumbnailUri { get; set; }
    public string Caption { get; set; }
    public List<string> Tags { get; set; } = new List<string>();
}

// In BlobInfoService.cs
public async Task<List<BlobInfo>> ListBlobsWithMetadataAsync(string containerName)
{
    List<BlobInfo> blobs = new List<BlobInfo>();
    BlobContainerClient containerClient = _blobServiceClient.GetBlobContainerClient(containerName);

    await foreach (var item in containerClient.GetBlobsAsync())
    {
        var blobClient = containerClient.GetBlobClient(item.Name);
        var blobProperties = await blobClient.GetPropertiesAsync();

        var blobInfo = new BlobInfo
        {
            ImageUri = blobClient.Uri.ToString(),
            ThumbnailUri = blobClient.Uri.ToString().Replace("/photos/", "/thumbnails/"),
            Caption = blobProperties.Value.Metadata.ContainsKey("Caption") ? blobProperties.Value.Metadata["Caption"] : item.Name
        };

        foreach (var key in blobProperties.Value.Metadata.Keys.Where(k => k.StartsWith("Tag")))
        {
            blobInfo.Tags.Add(blobProperties.Value.Metadata[key]);
        }

        blobs.Add(blobInfo);
    }

    return blobs;
}

Attempts to Resolve: I have verified that the BlobInfo class is properly compiled and that the Tags property is public and included in the class definition. The issue persists even after cleaning and rebuilding the solution. I suspect there might be a namespace mismatch or a project setup issue that I am overlooking.

Request: Could you please assist me in identifying the cause of this error and suggest a solution? Your guidance on this matter would be greatly appreciated.

Thank you for your time and assistance.

Answer 1

Welcome to the Microsoft Q&A Platform. Thank you for reaching out, and I hope you are doing well.

The error message suggests that the compiler cannot find a definition for the property or method named 'Tags' on the type 'BlobInfo'. I have tried reproducing the issue with the same code shared by using a single namespace in a console application (Refer Inline), but it seems like this issue cannot be reproduced as the structure shared is correct. Looking at the behavior, I am speculating an issue with the with code version reference mismatch.

//Save as BlobInfo.cs
using System.Collections.Generic;
namespace ConsoleApp1
{
     public class BlobInfo
    {
        public string ImageUri { get; set; }
        public string ThumbnailUri { get; set; }
        public string Caption { get; set; }
        public List<string> Tags { get; set; } = new List<string>();
    }
}

//Save as Program.cs
using System;
using System.Collections.Generic;
using System.Linq;
using Azure.Storage.Blobs;
using Azure.Storage.Queues;

namespace ConsoleApp1
{
    internal class Program
    {
        static string connectionString = "";
        public static void Main(string[] args)
        {
		ListBlobsWithMetadataAsync("test");
	}

        public static List<BlobInfo> ListBlobsWithMetadataAsync(string containerName)
        {
	    BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);
            List<BlobInfo> blobs = new List<BlobInfo>();
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);
             foreach (var item in containerClient.GetBlobs())
            {
                var blobClient = containerClient.GetBlobClient(item.Name);
                var blobProperties =  blobClient.GetProperties();
                var blobInfo = new BlobInfo
                {
                    ImageUri = blobClient.Uri.ToString(),
                    ThumbnailUri = blobClient.Uri.ToString(),
                    Caption = blobProperties.Value.Metadata.ContainsKey("Caption") ? blobProperties.Value.Metadata["Caption"] : item.Name
                };

                foreach (var key in blobProperties.Value.Metadata.Keys.Where(k => k.StartsWith("Tag")))
                {
                    blobInfo.Tags.Add(blobProperties.Value.Metadata[key]);
                }

                blobs.Add(blobInfo);
            }

            return blobs;
        }
    }   
}


Thanks