// @nuget: CommandLineParser -Version 2.8.0

using System;

using System.Collections.Generic;

using System.Threading.Tasks;

using CommandLine;

​

//Run WithParsedAsync  in v2.8+

public class Program

{

    public static async Task Main()

    {

        var args = "--userid=root -t int:long:string".Split();

        await Parser.Default.ParseArguments<Options>(args)

             .WithParsedAsync(RunAsync);

        Console.WriteLine($"Exit code= {Environment.ExitCode}");

    }

​

    //async method

    static async Task RunAsync(Options options)

    {

        Console.WriteLine("Starting async/await method");

        Console.WriteLine("Before async/await");

        await Task.Delay(0); //simulate async method    

        Console.WriteLine($"UserId={options.UserId}");

        await Task.Delay(0); //simulate async method    

        Console.WriteLine("After async/await");

    }

}

​

class Options

{

    [Option]

    public string UserId

    {

        get;

        set;

    }

​

    [Option('t', Separator = ':')]

    public IEnumerable<string> Types

    {

        get;

        set;

    }

}