I’m a big fan of cutting out unneeded or unnecessary code, so here is a tip that isn’t new in MVC4, but I just discovered it and thought it was really cool and worth sharing.  When using IOC in MVC, you setup a class that implements IDependencyResolver, which has methods to return services for a given type.  While these classes where simple, it always seemed like a bit of ceremony was required whenever starting up a new MVC app.

The following example shows what a DependencyResolver class looks like using my favorite IOC framework, Ninject:

   1:  public class NinjectDependencyResolver : IDependencyResolver

   2:      {

   3:          private readonly IKernel _kernel;

   4:   

   5:          public NinjectDependencyResolver(IKernel kernel)

   6:          {

   7:              _kernel = kernel;

   8:          }

   9:   

  10:          public object GetService(Type serviceType)

  11:          {

  12:              return _kernel.TryGet(serviceType);

  13:          }

  14:   

  15:          public IEnumerable<object> GetServices(Type serviceType)

  16:          {

  17:              return _kernel.GetAll(serviceType);

  18:          }

  19:      }

Nothing terribly complicated, but a lot of fluff.

I saw in a demo in last week’s C4MVC talk, that the DependencyResolver that was setup to create the APIController classes had some overrides I never saw before, and low and behold, the standard MVC DependencyResolver also has these overrides:

So instead of providing the SetResolver method with a DependencyResolver class, you can just provide it two delegate methods that would normally be in the DependencyResolver (GetService, and GetServices):

   1:  DependencyResolver.SetResolver(

   2:                  x => kernel.TryGet(x),

   3:                  x => kernel.GetAll(x));

POW!  Cut that 20+ line class down to a method that takes two parameters.  BAM!