ninject dependency resolver and service locator implementation - asp.net-mvc-3

Question

I am learning ASP.NE4 MVC3. I have created a NinjectDependencyResolver class, but I want to know how I would go about implementing the ServiceLocator class. Currently I get this error "The type SportsStore.WebUI.Infrastructure.NinjectDependencyResolver does not appear to implement Microsoft.Practices.ServiceLocation.IServiceLocator.
Parameter name: commonServiceLocator".
Global.asax
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
RegisterDependencyResolver();
//ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory());
}
private void RegisterDependencyResolver()
{
var kernel = new StandardKernel();
DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));
}
NinjectDepencyResolver cs
public class NinjectDependencyResolver
{
private readonly IKernel _kernel;
public NinjectDependencyResolver(IKernel kernel)
{
_kernel = kernel;
}
public object GetService(Type serviceType)
{
return _kernel.TryGet(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
try
{
return _kernel.GetAll(serviceType);
}
catch (Exception)
{
return new List<object>();
}
}

Answer 1

Your NinjectDependencyResolver must inherit from IDependencyResolver so your code should look like this:
public class NinjectDependencyResolver : IDependencyResolver

Answer 2

I would not do it like that. For one thing, Mark Seemann's book "Dependency Injection in .NET" clearly shows that Service Locator is actually an anti-pattern.
At any rate try not to bloat your global.asax file
If you instead used Nuget and got the latest version of NinjectMVC3 , you should end up with a clean Application_Start method
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
}
However, if you want to you can add in this line into the end of that method as I believe this is what Adam and Steve do in the Sportstore application in the Apress MVC3 book.
ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory());
Since that book was released, Ninject released newer versions that make it much easier, in fact I would guarantee that the Apress MVC4 book that ends up coming out will show the simpler way. The simple way is use nuget and get NinjectMVC3 , then it will have an App_Start folder which will run the files in them at start of the application.
Here is an example of it with some bindings
using Products.Data.Abstract;
using Products.Data.Concrete;
using Products.Data.Infrastructure;
[assembly: WebActivator.PreApplicationStartMethod(typeof(ProductsWeb.App_Start.NinjectMVC3), "Start")]
[assembly: WebActivator.ApplicationShutdownMethodAttribute(typeof(ProductsWeb.App_Start.NinjectMVC3), "Stop")]
namespace ProductsWeb.App_Start
{
using System.Reflection;
using Microsoft.Web.Infrastructure.DynamicModuleHelper;
using Ninject;
using Ninject.Web.Mvc;
public static class NinjectMVC3
{
private static readonly Bootstrapper bootstrapper = new Bootstrapper();
/// <summary>
/// Starts the application
/// </summary>
public static void Start()
{
DynamicModuleUtility.RegisterModule(typeof(OnePerRequestModule));
DynamicModuleUtility.RegisterModule(typeof(HttpApplicationInitializationModule));
bootstrapper.Initialize(CreateKernel);
}
/// <summary>
/// Stops the application.
/// </summary>
public static void Stop()
{
bootstrapper.ShutDown();
}
/// <summary>
/// Creates the kernel that will manage your application.
/// </summary>
/// <returns>The created kernel.</returns>
private static IKernel CreateKernel()
{
var kernel = new StandardKernel();
RegisterServices(kernel);
return kernel;
}
/// <summary>
/// Load your modules or register your services here!
/// </summary>
/// <param name="kernel">The kernel.</param>
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<IProductsRepository>().To<FakeProductsRepository>();
kernel.Bind<MovieRepository>().To<MovieRepository>();
}
}
}

Answer 3

Why not just use the official MVC Integration extension for Ninject, and the Common Service Locator implementation that comes in the official main distribution of Ninject (the dll is included in the build downloads)?