public class BlobStorageService
{
    public CloudBlobContainer GetCloudBlobContainer()
    {
        CloudStorageAccount storageAccount = CloudStorageAccount.Parse(System.Web.Configuration.WebConfigurationManager.AppSettings["BlobSetting"]);
        CloudBlobClient blobclient = storageAccount.CreateCloudBlobClient();
        CloudBlobContainer blobcontainer = blobclient.GetContainerReference("mycontainer");
        if (blobcontainer.CreateIfNotExists())
        {
            blobcontainer.SetPermissions(new BlobContainerPermissions { PublicAccess = BlobContainerPublicAccessType.Blob });
        }
        return blobcontainer;
    }

    public string GetReadData(string filename)
    {
        // Retrieve storage account from connection string.
        CloudStorageAccount storageAccount = CloudStorageAccount.Parse(System.Web.Configuration.WebConfigurationManager.AppSettings["BlobSetting"]);

        // Create the blob client.
        CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

        // Retrieve reference to a previously created container.
        CloudBlobContainer container = blobClient.GetContainerReference("mycontainer");

        // Retrieve reference to a blob named "myblob.csv"
        CloudBlockBlob blockBlob2 = container.GetBlockBlobReference(filename);

        string text;
        using (var memoryStream = new MemoryStream())
        {
            blockBlob2.DownloadToStream(memoryStream);
            text = System.Text.Encoding.UTF8.GetString(memoryStream.ToArray());
        }

        return text;
    }
}

[HttpPost]
public ActionResult UploadDevicesToRegister11(HttpPostedFileBase userDetailCsvfile)
{
    BlobStorageService df = new BlobStorageService();

    if (userDetailCsvfile.ContentLength > 0)
    {
        //To upload file on Blob
        CloudBlobContainer blobContainer = df.GetCloudBlobContainer();
        CloudBlockBlob blob = blobContainer.GetBlockBlobReference(userDetailCsvfile.FileName);
        blob.UploadFromStream(userDetailCsvfile.InputStream);

        //To read File from Blob
        blobContainerRead = df.GetReadData(userDetailCsvfile.FileName);
    }

    return View();
}