回复Microsoft botframework中的"正在键入"消息

我正在使用c#.net和LUIS认知服务上的MicrofsoftBotFramework开发一个聊天机器人.

我希望当用户输入时它应该回复为打字或机器人正在输入..

 public async Task Post([FromBody]Activity activity)
            {
                Trace.TraceInformation($"Type={activity.Type} Text={activity.Text}");

                if (activity.Type == ActivityTypes.Message)
                {
                    //await Microsoft.Bot.Builder.Dialogs.Conversation.SendAsync(activity, () => new ContactOneDialog());

                    //Implementation of typing indication
                    ConnectorClient connector = new ConnectorClient(new System.Uri(activity.ServiceUrl));
                    Activity isTypingReply = activity.CreateReply("Shuttlebot is typing...");
                    isTypingReply.Type = ActivityTypes.Typing;
                    await connector.Conversations.ReplyToActivityAsync(isTypingReply);

                    await Conversation.SendAsync(activity, () =>
                    new ExceptionHandlerDialog