1. 建立Dialogs資料夾，建立RootDialog

using System;
using System.Threading.Tasks;
using Microsoft.Bot.Builder.Dialogs;
using Microsoft.Bot.Connector;

namespace AzureBot_POC.Dialogs
{
    [Serializable]
    public class RootDialog : IDialog<object>
    {
        public Task StartAsync(IDialogContext context)
        {
            context.Wait(MessageReceivedAsync);

            return Task.CompletedTask;
        }

        private async Task MessageReceivedAsync(IDialogContext context, IAwaitable<object> result)
        {
            var activity = await result as Activity;

            // Calculate something for us to return
            int length = (activity.Text ?? string.Empty).Length;

            // Return our reply to the user
            await context.PostAsync($"You sent {activity.Text} which was {length} characters");

            context.Wait(MessageReceivedAsync);
        }
    }
}
 

2. Message Controller：
  

 [BotAuthentication]
    public class MessagesController : ApiController
    {
        /// <summary>
        /// POST: api/Messages
        /// Receive a message from a user and reply to it
        /// </summary>
        public async Task<HttpResponseMessage> Post([FromBody]Activity activity)
        {
            if (activity.GetActivityType() == ActivityTypes.Message)
            {
                await Conversation.SendAsync(activity, () => new Dialogs.RootDialog());
            }
            else
            {
                HandleSystemMessage(activity);
            }
            var response = Request.CreateResponse(HttpStatusCode.OK);
            return response;
        }

        private Activity HandleSystemMessage(Activity message)
        {
            string messageType = message.GetActivityType();
            if (messageType == ActivityTypes.DeleteUserData)
            {
                // Implement user deletion here
                // If we handle user deletion, return a real message
            }
            else if (messageType == 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
            }
            else if (messageType == ActivityTypes.ContactRelationUpdate)
            {
                // Handle add/remove from contact lists
                // Activity.From + Activity.Action represent what happened
            }
            else if (messageType == ActivityTypes.Typing)
            {
                // Handle knowing that the user is typing
            }
            else if (messageType == ActivityTypes.Ping)
            {
            }

            return null;
        }