텔레그램 봇 연동 후 유저 ID 구하기

using System;
using System.Threading;
using System.Threading.Tasks;
using Telegram.Bot;
using Telegram.Bot.Exceptions;
using Telegram.Bot.Polling;
using Telegram.Bot.Types;
using Telegram.Bot.Types.Enums;

namespace TelegramBotExample
{
    class Program
    {
        private static ITelegramBotClient botClient;

        static async Task Main(string[] args)
        {
            botClient = new TelegramBotClient("YOUR_BOT_API_KEY");

            using var cts = new CancellationTokenSource();

            // StartReceiving does not block the caller thread. Receiving is done on the ThreadPool.
            botClient.StartReceiving(
                HandleUpdateAsync,
                HandleErrorAsync,
                new ReceiverOptions
                {
                    AllowedUpdates = Array.Empty<UpdateType>() // receive all update types
                },
                cancellationToken: cts.Token
            );

            var me = await botClient.GetMeAsync();
            Console.WriteLine($"Start listening for @{me.Username}");
            Console.ReadLine();

            // Send cancellation request to stop bot
            cts.Cancel();
        }

        private static async Task HandleUpdateAsync(ITelegramBotClient botClient, Update update, CancellationToken cancellationToken)
        {
            if (update.Type == UpdateType.Message && update.Message?.Text != null)
            {
                var message = update.Message;

                Console.WriteLine($"Received a message from {message.Chat.Id}: {message.Text}");

                await botClient.SendTextMessageAsync(
                    chatId: message.Chat.Id,
                    text: "You said:\n" + message.Text,
                    cancellationToken: cancellationToken
                );
            }
        }

        private static Task HandleErrorAsync(ITelegramBotClient botClient, Exception exception, CancellationToken cancellationToken)
        {
            var errorMessage = exception switch
            {
                ApiRequestException apiRequestException
                    => $"Telegram API Error:\n[{apiRequestException.ErrorCode}]\n{apiRequestException.Message}",
                _ => exception.ToString()
            };

            Console.WriteLine(errorMessage);
            return Task.CompletedTask;
        }
    }
}