asp.net core經典hello world

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main()
        {
            new WebHostBuilder()
                .UseKestrel()
                .Configure(app => app.Run(context => context
                    .Response.WriteAsync("hello world!")))
                .Build()
                .Run();
        }
    }
}