How To Show Greet Message On Bot Chat

This is a very simple yet useful article. If you are new to learning bot framework, please follow my previous article.

 

When we launch any bot, asyncPost method is invoked on messagesController like below.

public async Task<HttpResponseMessage> Post([FromBody]Activity activity)
       {
           if (activity.Type == ActivityTypes.Message)
           {
               await Conversation.SendAsync(activity, () => new BingSearchDialog());
           }
           else
           {
               await HandleSystemMessage(activity);
           }
           var response = Request.CreateResponse(HttpStatusCode.OK);
           return response;
       }

In the above code, HandleSystemMessage method will be invoked by default.  

private async Task<Activity> HandleSystemMessage(Activity message)
      {
          if (message.Type == ActivityTypes.DeleteUserData)
          {
              // Implement user deletion here
              // If we handle user deletion, return a real message
          }
          else if (message.Type == ActivityTypes.ConversationUpdate)
          {
              // Handle conversation state changes, like members being added and removed
              // Use Activity.MembersAdded and Activity.MembersRemoved and Activity.Action for info
              // Not available in all channels
              IConversationUpdateActivity iConversationUpdated = message as IConversationUpdateActivity;
              if (iConversationUpdated != null)
              {
                  ConnectorClient connector = new ConnectorClient(new System.Uri(message.ServiceUrl));
                  foreach (var member in iConversationUpdated.MembersAdded ?? System.Array.Empty<ChannelAccount>())
                  {
                      // if the bot is added, then
                      if (member.Id == iConversationUpdated.Recipient.Id)
                      {
                          var reply = ((Activity)iConversationUpdated).CreateReply($"Hey Welcome to search chatbot.");
                          await connector.Conversations.ReplyToActivityAsync(reply);
                      }
                  }
              }
          }
          else if (message.Type == ActivityTypes.ContactRelationUpdate)
          {
              // Handle add/remove from contact lists
              // Activity.From + Activity.Action represent what happened
          }
          else if (message.Type == ActivityTypes.Typing)
          {
              // Handle knowing tha the user is typing
          }
          else if (message.Type == ActivityTypes.Ping)
          {
          }

          return null;
      }

Output