InlineKeyboard.cs

using System;
using System.Threading.Tasks;
using RxTelegram.Bot.Interface.BaseTypes;
using RxTelegram.Bot.Interface.BaseTypes.Requests.Callbacks;
using RxTelegram.Bot.Interface.BaseTypes.Requests.Messages;
using RxTelegram.Bot.Utils.Keyboard;

namespace RxTelegram.Bot.Examples.InlineKeyboard;

internal static class InlineKeyboard
{
    private static TelegramBot Bot { get; set; }
    private const string BotToken = "<PASTE YOUR BOT TOKEN HERE>";

    public static async Task Main()
    {
        Bot = new TelegramBot($"{BotToken}");
        var me = await Bot.GetMe();
        Console.WriteLine($"Bot name: @{me.Username}");

        var subscriptionMessage = Bot.Updates.Message.Subscribe(HandleReceivedMessage,
            exception => Console.WriteLine($"An error has occured: {exception.Message}"));
        var subscriptionCallbackQuery = Bot.Updates.CallbackQuery.Subscribe(HandleCallbackQuery,
            exception => Console.WriteLine($"An error has occured: {exception.Message}"));
        Console.ReadLine();
        subscriptionMessage.Dispose();
        subscriptionCallbackQuery.Dispose();
    }

    private static void HandleCallbackQuery(CallbackQuery callbackQuery)
    {
        Bot.AnswerCallbackQuery(new AnswerCallbackQuery
        {
            Text = callbackQuery.Data,
            CallbackQueryId = callbackQuery.Id
        });
    }

    private static void HandleReceivedMessage(Message message)
    {
        if (message.Text.Length != 0)
        {
            Bot.SendMessage(new SendMessage
            {
                ChatId = message.Chat.Id,
                Text = "Here is a inline keyboard!",
                ReplyMarkup = new InlineKeyboardMarkup
                {
                    InlineKeyboard = KeyboardBuilder.CreateInlineKeyboard()
                        .BeginRow()
                        .AddCallbackData("Abc", "You clicked on Abc")
                        .EndRow()
                        .BeginRow()
                        .AddCallbackData("1", "You clicked on 1")
                        .AddCallbackData("2", "You clicked on 2")
                        .EndRow()
                        .Build()
                }
            });
        }
    }
}