Creating Services

Services are long-lived classes listening for events Discord sends via the gateway, i.e. classes that inherit DiscordBotService.

See more: xref

I called the class I made HelloService. The name can be anything and you can have as many services as you want.

Now, paste the following code in:

using System;
using System.Linq;
using System.Threading.Tasks;
using Disqord;
using Disqord.Bot.Hosting;
using Disqord.Rest;

namespace MyBot
{
    // DiscordBotService is required to mark the class as a service.
    public class HelloService : DiscordBotService
    {
        // The phrases the service will respond to.
        private readonly string[] _phrases = { "hi", "hey", "hello" };

        // OnNonCommandReceived fires for messages that do not contain any of our prefixes etc.
        protected override async ValueTask OnNonCommandReceived(BotMessageReceivedEventArgs e)
        {
            // Ignores messages sent outside of guilds.
            // By default the bot ignores DMs anyways, but this is just an example.
            if (e.GuildId == null)
                return;

            // Ignores all system messages, e.g. pin or boost messages.
            if (e.Message is not IUserMessage)
                return;

            // Ignores messages sent by bots.
            // This also prevents the bot responding to itself infinitely.
            if (e.Message.Author.IsBot)
                return;

            // Ignores messages without any of the above defined phrases.
            if (!_phrases.Any(phrase => e.Message.Content.Contains(phrase, StringComparison.OrdinalIgnoreCase)))
                return;

            // Responds to the phrase by mentioning the author.
            await Bot.SendMessageAsync(e.ChannelId, new LocalMessage()
                .WithContent($"Hello, {e.Message.Author.Mention}!"));
        }
    }
}

This adds a basic service that responds to anyone saying hi, hey, or hello. Let's try it out! Boot up your bot and type any of the phrases in a channel.

Next up: Interactivity.