title: WebApi controller using a class library
body: <p>I'm trying to create a system that will allow me to host a "WebAPI" website either through a web application or through a windows service. To this end I want all my buisness logic to be contained within one class library so that I can reference this in both my windows service and my "web" (IIS) service.</p>
  
  <p>My current idea is using the self hosted options included in HttpSelfHostServer. For the web end I would just create a standard webapi website and add some reference to my class library.</p>
  
  <p>What I have found is that if I have the controller in the same namespace as the HttpSelfHostServer it works correctly but as soon as the controller is within an external class library the server can no longer resolve the route to my control / action.</p>
  
  <p>My code:</p>
  
  <p>Windows service:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.ComponentModel;
  using System.Data;
  using System.Diagnostics;
  using System.Linq;
  using System.ServiceProcess;
  using System.Text;
  using System.Reflection;
  using System.IO;
  
  using System.Web.Http.SelfHost;
  using System.Web.Http;
  using System.Web.Http.Dispatcher;
  
  using WebApiClasses;
  using WebApiClasses.Controllers;
  
  namespace WebAPISelfHost
  {
      public partial class Service1 : ServiceBase
      {
          private HttpSelfHostServer _server;
          private readonly HttpSelfHostConfiguration _config;
          public const string ServiceAddress = "http://localhost:8080";
  
          public Service1()
          {
              InitializeComponent();
  
              _config = new HttpSelfHostConfiguration(ServiceAddress);
  
              //AssembliesResolver assemblyResolver = new AssembliesResolver();
              //_config.Services.Replace(typeof(IAssembliesResolver), assemblyResolver);
  
              _config.Routes.MapHttpRoute("DefaultApi",
                  "api/{controller}/{id}",
                  new { id = RouteParameter.Optional });
  
          }
  
          protected override void OnStart(string[] args)
          {
              _server = new HttpSelfHostServer(_config);
              _server.OpenAsync();
          }
  
  
  
  
          protected override void OnStop()
          {
              _server.CloseAsync().Wait();
              _server.Dispose();
          }
      }
  
      //public class TestController : ApiController
      //{
      //    public string Get()
      //    {
      //        return "This is an internal test message.";
      //    }
      //}
  
      class AssembliesResolver : DefaultAssembliesResolver
      {
          public override ICollection&lt;Assembly&gt; GetAssemblies()
          {
              ICollection&lt;Assembly&gt; baseAssemblies = base.GetAssemblies();
              List&lt;Assembly&gt; assemblies = new List&lt;Assembly&gt;(baseAssemblies);
  
              // Add whatever additional assemblies you wish
  
              var controllersAssembly = Assembly.LoadFrom(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) + @"\WebApiClasses.dll");
              baseAssemblies.Add(controllersAssembly);
              return assemblies;
          }
      }
  }
  </code></pre>
  
  <p>Controller:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  
  using System.Web.Http;
  
  namespace WebApiClasses.Controllers
  {
      public class TestController : ApiController
      {
          public string Get()
          {
              return "hello from class library";
          }
      }
  }
  </code></pre>
  
  <p>When I try to navigate to: "http://localhost:8080/api/" I get:</p>
  
  <p>
  
  No HTTP resource was found that matches the request URI 'http://localhost:8080/api/'.
  
  
  No type was found that matches the controller named 'Test'.
  
  </p>
  
  <p>Any suggestions? I think I should be able to do this.</p>