Display Welcome Message in v4 Bot Framework Bot (C# + .Net Core Web Application)

Question

I had created a bot with v3 (C#) SDK and the welcome message used to work just fine without any sweat. And it still does for me in production. The code is handled in HandleS

Answer 1

In v4 of the Bot Framework SDK this functionality is handled by making your bot class inherit from the ActivityHandler class then overriding the OnMembersAddedAsync method.

How this looks in practice is:

...

public class MyBot : ActivityHandler
{
    ...

        protected override async Task OnMembersAddedAsync(IList membersAdded, ITurnContext turnContext, CancellationToken cancellationToken)
        {
            foreach (var member in membersAdded)
            {
                // Greet anyone that was not the target (recipient) of this message.
                if (member.Id != turnContext.Activity.Recipient.Id)
                {
                    var welcomeMessage = "Hello and welcome!";

                    await turnContext.SendActivityAsync(welcomeMessage, cancellationToken);
                }
            }
        }
    ...
}

There are examples of how to do this here, here, and here.

You may have to update the version of the Microsoft.Bot.Builder package that you are using.