private async Task MessageReceivedAsync
            (IDialogContext context, IAwaitable <IMessageActivity> result)
        {
            var messageResult = await result;

            var cvs = new OCRService();

            var finalResult = string.Empty;

            // 上傳圖片的處理
            if (messageResult.Attachments?.Any(a => a.ContentType.Contains("image")) ?? false)
            {
                var attachment =
                    messageResult.Attachments.FirstOrDefault(x => x.ContentType.Contains("image"));

                var imageStream = await
                                  messageResult.GetConnector().GetImageStream(attachment);

                var ocrResult = await cvs.GetOcrResultAsync(imageStream, "zh-Hant");

                finalResult = ProcessImageOcrResult(context, ocrResult);
            }
            // 圖片網址的處理
            else if (Uri.IsWellFormedUriString(messageResult.Text, UriKind.Absolute))
            {
                var ocrResult = await cvs.GetOcrResultAsync(messageResult.Text, "zh-Hant");

                finalResult = ProcessImageOcrResult(context, ocrResult);
            }

            context.Done(finalResult);
        }