Using Autofac with webapi and mvc5.1 not working for webapi - autofac

Question

I have a project using both mvc and webapi.
It's a Membership Reboot application so I have taken the example single application project and have slightly modified it to suit.
The DI works ok for controllers however when I try to call a webapi controller I keep getting an error
Make sure that the controller has a parameterless public constructor.
Is there something else I need to do for using autofac with webapi?
This is the code from my startup.cs
public void Configuration(IAppBuilder app)
{
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationType = "External",
AuthenticationMode = Microsoft.Owin.Security.AuthenticationMode.Passive
});
ConfigureMembershipReboot(app);
}
private static void ConfigureMembershipReboot(IAppBuilder app)
{
System.Data.Entity.Database.SetInitializer(new System.Data.Entity.MigrateDatabaseToLatestVersion<DefaultMembershipRebootDatabase, BrockAllen.MembershipReboot.Ef.Migrations.Configuration>());
//System.Data.Entity.Database.SetInitializer(new System.Data.Entity.CreateDatabaseIfNotExists<DefaultMembershipRebootDatabase>());
var cookieOptions = new CookieAuthenticationOptions
{
AuthenticationType = MembershipRebootOwinConstants.AuthenticationType
};
BuildAutofacContainer(app, cookieOptions.AuthenticationType);
app.UseMembershipReboot(cookieOptions);
}
private static void BuildAutofacContainer(IAppBuilder app, string authType)
{
var builder = new ContainerBuilder();
var config = CreateMembershipRebootConfiguration(app);
builder.RegisterInstance(config).As<MembershipRebootConfiguration>();
builder.RegisterType<DefaultUserAccountRepository>()
.As<IUserAccountRepository>()
.As<IUserAccountQuery>()
.InstancePerLifetimeScope();
builder.RegisterType<UserAccountService>().OnActivating(e =>
{
var owin = e.Context.Resolve<IOwinContext>();
var debugging = false;
#if DEBUG
debugging = true;
#endif
e.Instance.ConfigureTwoFactorAuthenticationCookies(owin.Environment, debugging);
})
.AsSelf()
.InstancePerLifetimeScope();
builder.Register(ctx =>
{
var owin = ctx.Resolve<IOwinContext>();
return new OwinAuthenticationService(authType, ctx.Resolve<UserAccountService>(), owin.Environment);
})
.As<AuthenticationService>()
.InstancePerLifetimeScope();
builder.Register(ctx=>HttpContext.Current.GetOwinContext()).As<IOwinContext>();
builder.RegisterControllers(typeof(Startup).Assembly);
builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
var container = builder.Build();
System.Web.Mvc.DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}

Answer 1

It was a 1 liner :)
GlobalConfiguration.Configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);