How do I get my commands to work in Discord.Net

Question

So I THINK I know what may be the problem but I'm unsure how to go about fixing it. I'm very new to C# coding. I've been coding Discord bots in node for over a year now so switching over is kinda difficult. I'm following the instructions from the Discord.NET documentations and guide. Here is the code in the Program file

using System;
using System.Threading.Tasks;
using Discord;
using Discord.WebSocket;

namespace GalacticBot
{
    class MainClass
    {
        public static void Main(string[] args) => new MainClass().MainAsync().GetAwaiter().GetResult();

        private DiscordSocketClient client;

        // Calls the class holding information
        private Config config = new Config();

        public async Task MainAsync()
        {
            client = new DiscordSocketClient();

            // Logs to console
            client.Log += Log;

            // Uses the token to start the bot
            await client.LoginAsync(TokenType.Bot, config.TestToken);
            await client.StartAsync();

            await Task.Delay(-1);
        }

        private Task Log(LogMessage msg)
        {
            Console.WriteLine(msg.ToString());
            return Task.CompletedTask;
        }
    }
}

Here is the code in the CommandHandler file

using System;
using System.Reflection;
using System.Threading.Tasks;
using Discord;
using Discord.Commands;
using Discord.WebSocket;

namespace GalacticBot
{
    public class CommandHandler
    {
        private readonly DiscordSocketClient client;
        private readonly CommandService commands;

        private readonly Config config = new Config();

        public CommandHandler(DiscordSocketClient _client, CommandService _commands)
        {
            client = _client;
            commands = _commands;
        }

        public async Task InstallCommandsAsync()
        {
            client.MessageReceived += HandleCommandAsync;

            await commands.AddModulesAsync(assembly: Assembly.GetEntryAssembly(), services: null);
        }

        private async Task HandleCommandAsync(SocketMessage MessageParam)
        {
            var message = MessageParam as SocketUserMessage;
            if (message == null) return;

            int ArgPos = 0;

            // If there's no prefix or the message is from a bot then nothing happens
            if (!(message.HasCharPrefix('!', ref ArgPos) || message.HasMentionPrefix(client.CurrentUser, ref ArgPos)) || message.Author.IsBot) return;

            var context = new SocketCommandContext(client, message);

            await commands.ExecuteAsync(
                context: context,
                argPos: ArgPos,
                services: null
                );
        }
    }
}

and here is the code for the commands themselves

using System;
using System.Threading.Tasks;
using Discord.Commands;

public class Hi : ModuleBase<SocketCommandContext>
{
    [Command("hey")]
    [Summary("Just says hi.")]

    public async Task SayAsync()
    {
        Console.WriteLine("Command used");
        await Context.Channel.SendMessageAsync("Just saying hi!");
    }
}

The Console.WriteLine in the command is for testing purposes to see if it's even attempting to work. My thought is that I'm not calling and using the CommandHandler class anywhere. I don't know if this is the problem and if it is, I don't know what I need to do.

Answer 1

After a lot more Googling and trying a bunch of different ideas, I finally found a solution. Anu6is was right in that you have to create a new instance and call the install method. This led to returning null when starting the bot. First I made a variable for commands and made it static with the _client variable as well as making a variable for the CommandHandler

private static DiscordSocketClient _client;
private static CommandService _commands;

private CommandHandler commandHandler;

Inside MainAsync I had to create a new instance of the CommandService, a new instance of the command handler passing _client and _commands and then call the InstallCommandsAsync method

_commands = new CommandService();

commandHandler = new CommandHandler(_client, _commands);
await commandHandler.InstallCommandsAsync();

After the changes, build came back successful with no warnings and the test command worked. Hope this helps someone else at some point.