QnABot.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.
//
// Generated with Bot Builder V4 SDK Template for Visual Studio EchoBot v4.5.0

using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Bot.Builder;
using Microsoft.Bot.Builder.Dialogs;
using Microsoft.Bot.Schema;

namespace Microsoft.BotBuilderSamples.Bots
{
    public class QnABot<T> : ActivityHandler where T : Microsoft.Bot.Builder.Dialogs.Dialog
    {
        protected readonly BotState ConversationState;
        protected readonly Microsoft.Bot.Builder.Dialogs.Dialog Dialog;
        protected readonly BotState UserState;

        public QnABot(ConversationState conversationState, UserState userState, T dialog)
        {
            ConversationState = conversationState;
            UserState = userState;
            Dialog = dialog;
        }

        public override async Task OnTurnAsync(ITurnContext turnContext, CancellationToken cancellationToken = default)
        {
            await base.OnTurnAsync(turnContext, cancellationToken);

            // Save any state changes that might have occurred during the turn.
            await ConversationState.SaveChangesAsync(turnContext, false, cancellationToken);
            await UserState.SaveChangesAsync(turnContext, false, cancellationToken);
        }

        protected override async Task OnMessageActivityAsync(ITurnContext<IMessageActivity> turnContext, CancellationToken cancellationToken) =>
            // Run the Dialog with the new message Activity.
            await Dialog.RunAsync(turnContext, ConversationState.CreateProperty<DialogState>(nameof(DialogState)), cancellationToken);

        protected override async Task OnMembersAddedAsync(IList<ChannelAccount> membersAdded, ITurnContext<IConversationUpdateActivity> turnContext, CancellationToken cancellationToken)
        {
            foreach (var member in membersAdded)
            {
                if (member.Id != turnContext.Activity.Recipient.Id)
                {
                    await turnContext.SendActivityAsync(MessageFactory.Text($"Hello and welcome!"), cancellationToken);
                }
            }
        }
    }
}