Azure Blob storage: DownloadToByteArray VS DownloadToStream

Question

I have been playing with the Azure Blob Storage service to save/recover files in a context of a web page to be hosted in Azure Web Pages.

During the learning process I h

Answer 1

Instead of streaming the blob through your server, you could download it directly from the blob storage. My answer is built on top of Steve's response here: Downloading Azure Blob files in MVC3. For downloading a blob directly from the storage, you would utilize Shared Access Signature (SAS). Recently Azure Storage has introduced an enhancement, which allows you to specify Content-Disposition header in SAS. See this modified code.

    public static string GetDownloadLink(string fileName)
    {
        CloudBlobContainer container = GetBlobContainer();
        CloudBlockBlob blockBlob = container.GetBlockBlobReference(fileName);
        //Create an ad-hoc Shared Access Policy with read permissions which will expire in 12 hours
        SharedAccessBlobPolicy policy = new SharedAccessBlobPolicy()
        {
            Permissions = SharedAccessBlobPermissions.Read,
            SharedAccessExpiryTime = DateTime.UtcNow.AddHours(12),
        };
        //Set content-disposition header for force download
        SharedAccessBlobHeaders headers = new SharedAccessBlobHeaders()
        {
            ContentDisposition = string.Format("attachment;filename=\"{0}\"", fileName),
        };
        var sasToken = blockBlob.GetSharedAccessSignature(policy, headers);
        return blockBlob.Uri.AbsoluteUri + sasToken;
    }

    public ActionResult Download(string fileName)
    {
        var sasUrl = GetDownloadLink(fileName);
        //Redirect to SAS URL ... file will now be downloaded directly from blob storage.
        Redirect(sasUrl);
    }