using System;

using System.Collections.Generic;

using System.Net;

using System.Net.NetworkInformation;

using System.Threading.Tasks;

using System.Threading.Tasks.Dataflow;

using System.Text.RegularExpressions;

using System.Linq;

using System.Globalization;

​

public class Program

{

    private static List<IPStatus> _results;

    public static async Task MyMethodAsync(IPAddress ip)

    {

        await Task.Delay(500);

        Console.WriteLine("processing");

    }

​

    public static async Task Asd()

    {

        var options = new ExecutionDataflowBlockOptions{MaxDegreeOfParallelism = 2};

        var block = new ActionBlock<IPAddress>(ip => MyMethodAsync(ip), options);

        var list = new List<IPAddress>{IPAddress.Loopback, IPAddress.Loopback, IPAddress.Loopback, IPAddress.Loopback, IPAddress.Loopback, IPAddress.Loopback, IPAddress.Loopback, IPAddress.Loopback, IPAddress.Loopback};

        foreach (var ip in list)

        {

            block.Post(ip);

        }

​

        block.Complete();

        await block.Completion;

    }

​

    public static void Main()

    {

        List<string> ListTest = new List<string>();

        ListTest.Add("01293821921DE is refunded successfully");

        ListTest.Add("0123821921DE is refunded successfully");

        ListTest.Add("01693821921DE is refunded successfully");

        Console.WriteLine("\n List in Order \n");

        foreach(var item in ListTest)

        {

            Console.WriteLine(item);

        }

        Console.WriteLine("\n List in Reverse Order \n");

        for(int i = ListTest.Count() - 1; i >= 0; i-- )

        {

            Console.WriteLine(ListTest[i]);

        }

    }

}