using System;

using System.Collections.Generic;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

        static async Task MainAsync2()

        {

            var param = "Hi";

            ThreadPool.QueueUserWorkItem((x) => MethodWithParameter((string) x), param);

            param = "Changed";

            await Task.Delay(10000);

        }

​

        static void MethodWithParameter(string param)

        {

            Console.WriteLine(param);

        }

​

        public static void Main(string[] args)

        {

            MainAsync2().Wait();

        }

}