Azure storage DownloadToStreamAsync每次都会失败(无一例外)

以下方法应将csv文件从Azure存储下载到内存流。

public async Task<AzureResponse> ReadCsvFileToStreamFromBlobAsync(CloudBlobContainer container, string fileName)
    {
        var ar = new AzureResponse();
        // Retrieve reference to a blob (fileName)
        var blob = container.GetBlockBlobReference(fileName);
        if (blob != null)
        {
            string message;
            try
            {
                using (var memoryStream = new MemoryStream())
                {
                   **// code gets here and then falls right through to the end of the
                   //calling method, bypassing the catch portion here** 
                   await blob.DownloadToStreamAsync(memoryStream)                          
                    **//Tried adding .ConfigureAwait(false); to the above call                    //downloads blob's content to a stream
                   //that did not work
                   //per this SO post, https://stackoverflow.com/questions/28526249/azure-downloadtostreamasync-method-hangs

                    //code doesn't reach here**
                    message = message = $"Csv file read to Stream correctly. Filename:  {fileName}.";
                    ar.Status = true;
                    ar.Message = message;
                    ar.FileAsStream = memoryStream;
                    return ar;

                }
            }
            catch (Exception ex)
            {
                message = $"Csv file was not loaded to the memory stream on {DateTime.Now} for file {fileName} with exception message {ex.Message}";
                ar.Status = false;
                ar.Message = message;
                ar.FileAsStream = null;
                return ar;
            }
        }

        ar.Status = false;
        ar.Message = $" File not found error for {fileName} on {DateTime.Now}";
        ar.FileAsStream = null;
        return ar;
    }

注: 这个方法在我的Main方法(它是一个控制台应用程序)中用以下几行代码调用

 az = new AzureStorageCommon(config);
        var fileContainer = az.GetAzureFilesContainer();
        var afs = new AzureFileMethods();
        var returned = afs.ReadCsvFileToStreamFromBlobAsync(fileContainer, "EarningsEvents_Dec_2018.csv");

这是返回给调用方法的内容

Id=37,Status=WaitingForActivation,Method=“{null}”,Result=“{Not yet computed}”

1. 是因为它是一个csv文件吗?(我怀疑)
3. 如何使用cancellation令牌来运行它,以确保文件在代码完成之前实际完成。