How to download a file from Blob Storage to the browser

Question

Here is how I am listing available files:

var azureConnectionString = CloudConfigurationManager.GetSetting("AzureBackupStorageConnectString");
var containerName = ConfigurationManager.AppSettings["FmAzureBackupStorageContainer"];
if (azureConnectionString == null || containerName == null)
    return null;

CloudStorageAccount backupStorageAccount = CloudStorageAccount.Parse(azureConnectionString);
var backupBlobClient = backupStorageAccount.CreateCloudBlobClient();
var container = backupBlobClient.GetContainerReference(containerName); 
var blobs = container.ListBlobs(useFlatBlobListing: true);
var downloads = blobs.Select(blob => blob.Uri.Segments.Last()).ToList();

I need to know how to pass that file down to the browser for a user to download without necessarily saving it to the server.

Answer 1

If you use ASP.NET (core), you can stream the content to the browser without saving the file on the server and using FileStreamResult which is IActionResult would be more elegant solution.

var stream = await blob.OpenReadAsync();
return File(stream, blob.Properties.ContentType, option);

This is the best solution if you don't want to risk your SAS tokens getting stolen, they are just in the query string after all so are not encrypted even with https.