using System;

using System.Linq;

using System.Collections.Generic;

using System.IO;

using System.Threading.Tasks;

using System.Text;

public class Program

{

    public async static Task Main()

    {

        var arr = new List<int>{1,2,3};

        var resp = await Task.WhenAll(arr.Select(async x => 

        {

            await Task.Delay(100); // repository access

            Console.WriteLine($"loop finish");

            return x;

        }));

        Console.WriteLine("Finish");

    }

}

​