Exception is: InvalidOperationException - The current type, is an interface and cannot be constructed. Are you missing a type mapping?

Question

In my bootstrapper:

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 MVC
                DependencyResolver.SetResolver(new UnityDependencyResolver(container));

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

                #region managers
                container.RegisterType<ISettingsManager, SettingsManager>();

                container.RegisterType<IMamDataManager, MamDataManager>();

                container.RegisterType<IAppsDataManager, AppsDataManager>();
                #endregion

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

in my controller's code:

ISettingsManager sm = mUnityContainer.Resolve<ISettingsManager>();

hovering on mUnityContainer I see ISettingsManager is mapped to SettingsManager

but then I get the error:

Exception is: InvalidOperationException - The current type, is an interface and cannot be constructed. Are you missing a type mapping?

I have also tried

ISettingsManager sm = (ISettingsManager)mUnityContainer.Resolve<>(typeof(ISettingsManager));

but no use

Answer 1

Just for others (like me) who might have faced the above error. The solution in simple terms.

You might have missed to register your Interface and class (which implements that inteface) registration in your code.

e.g if the error is
"The current type, xyznamespace. Imyinterfacename, is an interface and cannot be constructed. Are you missing a type mapping?"

Then you must register the class which implements the Imyinterfacename in the UnityConfig class in the Register method. using code like below

 container.RegisterType<Imyinterfacename, myinterfaceimplclassname>();