CLoudBLob Storage Fetch Properties (404 Error)

Question

I am trying to get a file by URL using the following code:

public async Task<string> GetInlineImageSrcAsync(string url)
    {
        //Instance objects needed to store the files
        var storageAccount = new CloudStorageAccount(new StorageCredentials(AccountName, Key), true);
        CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
        CloudBlobContainer imagesContainer = blobClient.GetContainerReference(ProfilePicsContainer);
        CloudBlob cloudBlob = imagesContainer.GetBlobReference(url);
        cloudBlob.FetchAttributes();
        long fileByteLength = cloudBlob.Properties.Length;
        byte[] bytes = new byte[fileByteLength];
        for (int i = 0; i < fileByteLength; i++)
        {
            bytes[i] = 0x20;
        }


        //var bytes = await _httpClient.GetByteArrayAsync(url);
        var base64 = Convert.ToBase64String(bytes);
        //var mimeType = "image/png";
        // If mime types differ, try this
        var mimeType = $"image/{ParseExtensionFromUrl(url)}";
        var inlineImageSrc = $"data:{mimeType};base64,{base64}";
        return inlineImageSrc;
    }

However in the fetchproperties method, it always throws an exception (404).

WHen I do remote debugging I can see cloudBlob is actually not null, so that means the file is found!

stack trace

StackTrace = " at Microsoft.WindowsAzure.Storage.Core.Executor.Executor.ExecuteSync[T](RESTCommand`1 cmd, IRetryPolicy policy, OperationContext operationContext) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Core\Exec...

Gaurav Mantri Gaurav Mantri · Accepted Answer · 2019-11-20T10:49:35

If the URI represents a blob URI, then you will have to use CloudBlob constructor to create an instance. So your code would be:

CloudBlob blob = new CloudBlob(new Uri(url), blobClient);

The reason you're getting this error is because GetBlobReference method expects the name of the blob and not the full URI.

CLoudBLob Storage Fetch Properties (404 Error)

1 Answers