static void Main(string[] args)

        {

            //Assembly.Load("WebApplication1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null");    //加载外部程序集

            var config = new HttpSelfHostConfiguration("http://localhost:8080");

            config.Routes.MapHttpRoute(

                "API Default", "api/{controller}/{id}",

                new { id = RouteParameter.Optional });

            using (var server = new HttpSelfHostServer(config))

            {

                server.OpenAsync().Wait();

                Console.WriteLine("Press Enter to quit.");

                Process.Start("http://localhost:8080/api/xx");

                Console.ReadLine();

            }

        }

 public class xxController: Controller

    {

        public IEnumerable<string> Get()

        {

            return new string[] { "", "" };

        }

    }

var baseAddress = ConfigurationManager.AppSettings["baseAddress"];

            var config = new HttpSelfHostConfiguration(baseAddress);

            config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));

            config.Routes.MapHttpRoute(

                name: "DefaultApi",

                routeTemplate: "api/{controller}/{action}/{id}",

                defaults: new { id = RouteParameter.Optional }

            );

            var cors = new EnableCorsAttribute("*", "*", "*");//**********

            config.EnableCors(cors);

            var server = new HttpSelfHostServer(config);

            server.OpenAsync().Wait();

class Startup

{

    //  Hack from http://stackoverflow.com/a/17227764/19020 to load controllers in

    //  another assembly.  Another way to do this is to create a custom assembly resolver

    Type valuesControllerType = typeof(OWINTest.API.ValuesController);

    // This code configures Web API. The Startup class is specified as a type

    // parameter in the WebApp.Start method.

    public void Configuration(IAppBuilder appBuilder)

    {

        // Configure Web API for self-host.

        HttpConfiguration config = new HttpConfiguration();

        //  Enable attribute based routing

        //  http://www.asp.net/web-api/overview/web-api-routing-and-actions/attribute-routing-in-web-api-2

        config.MapHttpAttributeRoutes();

        config.Routes.MapHttpRoute(

            name: "DefaultApi",

            routeTemplate: "api/{controller}/{id}",

            defaults: new { id = RouteParameter.Optional }

        );

        appBuilder.UseWebApi(config);

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Web.Http;

namespace OWINTest.Service.API

{

    [RoutePrefix("api/testing")]

    public class RoutedController : ApiController

    {

        [Route("getall")]

        public IEnumerable<string> GetAllItems()

        {

            return new string[] { "value1", "value2" };

        }

    }

}

public partial class APIServiceTest : ServiceBase

{

    public string baseAddress = "http://localhost:9000/";

    private IDisposable _server = null;

    public APIServiceTest()

    {

        InitializeComponent();

    }

    protected override void OnStart(string[] args)

    {

        _server = WebApp.Start<Startup>(url: baseAddress);

    }

    protected override void OnStop()

    {

        if(_server != null)

        {

            _server.Dispose();

        }

        base.OnStop();

    }

}