Getting parameterles public constructor error - asp.net

Question

An error occurred when trying to create a controller of type
'ChatBotController'. Make sure that the controller has a
parameterless public constructor.
at
System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage
request, HttpControllerDescriptor controllerDescriptor, Type
controllerType) ↵ at
System.Web.Http.Controllers.HttpControllerDescriptor.CreateController(HttpRequestMessage
request) ↵ at
System.Web.Http.Dispatcher.HttpControllerDispatcher.d__15.MoveNext()
When I try to reach my IFeedbackRepository I get the error aboe. It happens when I put in the constructor in my ChatBotController.cs
public class ChatBotController : ApiController
{
IFeedbackRepository _feedbackRepository;
public ChatBotController(IFeedbackRepository feedbackRepository)
{
_feedbackRepository = feedbackRepository;
}
[HttpPost]
public IHttpActionResult PostQuestion([FromBody]string message) //TODO: make sure that webapi will search the message in the body of the http request
{
throw new NotImplementedException();
}
}
I'm using both MVC and Api which I both resolve in my Global.asax:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
GlobalConfiguration.Configure(WebApiConfig.Register);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
DependencyConfig.RegisterWebApiDependencies();
DependencyConfig.RegisterMvcDependencies();
}
This is my DependencyConfig.cs for both MVC and Api:
public static void RegisterWebApiDependencies()
{
var container = new Container();
container.Options.DefaultScopedLifestyle = new AsyncScopedLifestyle();
container.Register<IAnswerGenerator, PxlAnswerGenerator>(Lifestyle.Scoped);
container.Register<ChatBotDbContext>(Lifestyle.Scoped);
container.Register<IFeedbackRepository, FeedbackDbRepository>(Lifestyle.Scoped);
container.Verify();
DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));
}
public static void RegisterMvcDependencies()
{
var container = new Container();
container.Options.DefaultScopedLifestyle = new WebRequestLifestyle();
container.Register<IFeedbackRepository, FeedbackDbRepository>(Lifestyle.Scoped);
container.Register<ChatBotDbContext>(Lifestyle.Scoped);
container.RegisterMvcControllers(Assembly.GetExecutingAssembly());
container.Verify();
DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));
}
What am I doing wrong?

Answer 1

According to the documentation of Simple-Injector when you want to initialize the resolver for the WebApi part of your registration you need to call
container.RegisterWebApiControllers(GlobalConfiguration.Configuration);
container.Verify();
DependencyResolver.SetResolver(new SimpleInjectorWebApiDependencyResolver(container));

Answer 2

I don't see you calling container.RegisterWebApiControllers(GlobalConfiguration.Configuration); in RegisterWebApiDependencies(). This is required.
You may want to review the simpleinjector documentation for integrating with ASP.NET Web API and MVC here:
https://simpleinjector.readthedocs.io/en/latest/webapiintegration.html
Also the documentation above has the container/DI setup at the beginning of application_start(). If the above change alone does not work, you may want to try putting the following two lines at the start of application_start():
DependencyConfig.RegisterWebApiDependencies();
DependencyConfig.RegisterMvcDependencies();