WebApi.UnityDependencyResolver does not implement Microsoft.Practices.ServiceLocation.IServiceLocator. Parameter : commonServiceLocator

Question

I try to run the following code:

using System.Web.Http;
using System.Web.Mvc;
using Conduit.Mam.ClientSerivces.Dal.Configuration;
using MamInfrastructure.Common.Dal;
using MamInfrastructure.Common.Logger;
using MamInfrastructure.Logger;
using Microsoft.Practices.Unity;
using Unity.WebApi;

namespace Conduit.Mam.ClientServices.Common.Initizliaer
{
    public static class Initializer
    {
        private static bool isInitialize;
        private static readonly object LockObj = new object();
        private static IUnityContainer defaultContainer = new UnityContainer();

        static Initializer()
        {
            Initialize();
        }

        public static void Initialize()
        {
            if (isInitialize)
                return;

            lock (LockObj)
            {
                IUnityContainer container = defaultContainer;

                //registering Unity for web API
                GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
                //registering Unity for MVC
                DependencyResolver.SetResolver(new UnityDependencyResolver(container));

                container.RegisterType<IDal<ClientService.DAL.EntityFramework.MamConfiguration>, MamConfigurationDal>();
                container.RegisterType<IApplicationLogger, Log4NetLogger>();

                if (!isInitialize)
                {
                    isInitialize = true;
                }
            }
        }
    }
}

ad get the following exception:

The type Unity.WebApi.UnityDependencyResolver does not appear to implement Microsoft.Practices.ServiceLocation.IServiceLocator. Parameter name: commonServiceLocator

I have tried to install webApi package but it didn't help

Answer 1

In your Initialize method replace:

GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);

with:

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

Now you understand what the problem is:

System.Web.Http.Dependencies.IDependencyResolver (used by the Web API) and System.web.Mvc.IDependencyResolver (used by ASP.NET MVC) are two completely different types (even if they have the same name) and yet you attempt to assign both of them to the same type (UnityDependencyResolver) which obviously cannot work.

Answer 2

I had a similar issue, but in my case my web application has MVC and WebApi Controllers. I resolved like this:

using Microsoft.Practices.Unity;
using System.Web.Http;
using System.Web.Mvc;
using Unity.Mvc5;

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

Where the first line is going to use the MVC DependencyResolver and in the second line I use the WebApi UnityDependencyResolver.