ASP.Net MVC 4 Web API controller doesn't work with Unity.WebApi

api, asp.net, c#, json, unity-container

Solution

The handling of Controller and ApiController is different as they have completely different base classes:

I use Unity.MVC4 library for controller DI (http://www.nuget.org/packages/Unity.MVC4/)

Install-Package Unity.MVC4

and Unity.WebAPI for DI (http://www.nuget.org/packages/Unity.WebAPI/)

Install-Package Unity.WebAPI

Your bootstrapper should be a combination of both:

DependencyResolver.SetResolver(new Unity.Mvc4.UnityDependencyResolver(container));
GlobalConfiguration.Configuration.DependencyResolver = new Unity.WebApi.UnityDependencyResolver(container);

Note I also had to do to add some registration to get the Help page to work

container.RegisterInstance(typeof (HttpConfiguration), GlobalConfiguration.Configuration);

As the owner of Unity.MVC4 I am looking at getting WebApi implemented within our library.

Problem

My ASP.Net MVC 4 Web API controller doesn't work with Unity.WebApi. In the same project simple controllers works with Unity.Mvc3 properly. But when I run Web API controller derived from ApiController I'm getting a message: {"$id":"1","Message":"An error has occurred.","ExceptionMessage":"Type 'ElectricTests.Controllers.Api.DocumentsController' does not have a default constructor","ExceptionType":"System.ArgumentException","StackTrace":" at System.Linq.Expressions.Expression.New(Type type)\r\n at System.Web.Http.Internal.TypeActivator.Create[TBase](Type instanceType)\r\n at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.GetInstanceOrActivator(HttpRequestMessage request, Type controllerType, Func`1& activator)\r\n at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)"} My ApiController: ``` public class DocumentsController : ApiController { private readonly IDocumentsRepository _repository; public DocumentsController(IDocumentsRepository repository) { _repository = repository; } public IEnumerable<FormattedDocument> GetFormattedDocuments() { return _repository.GetAllFormattedDocuments(); } ... ``` Bootstrapper.cs: ``` public static class Bootstrapper { public static void Initialise() { IUnityContainer container = BuildUnityContainer(); DependencyResolver.SetResolver(new UnityDependencyResolver(container)); } private static IUnityContainer BuildUnityContainer() { var container = new UnityContainer(); // register all your components with the container here // it is NOT necessary to register your controllers // e.g. container.RegisterType<ITestService, TestService>(); container.RegisterType<IDocumentsRepository, DocumentsRepository>(); container.RegisterType<IQuestionsRepository, QuestionsRepository>(); container.RegisterType<ITestRepository, TestsRepository>(); return container; } } ``` Where is my mistake?

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