Dependency injection with multiple repositories

Question

I have a wcf service and on the client i have:

var service = new ServiceReference1.CACSServiceClient()

The actual service code is:

Answer 1

Do your repositories have object-level state? Probably not, so create them as singletons and have a DI container provide them to CACService.

Otherwise, are they actually expensive to create? If not, creating a new one per request has negligible cost compared to the RPC and database operations.

Using the Ninject dependency injection container, your CACService might look like the following. Other DI containers have equally succinct mechanisms of doing this.

public class CACSService
{
    public CACService
    {
        // need to do this since WCF creates us
        KernelContainer.Inject( this );
    }

    [Inject]
    public IUserRepository Repository
    { set; get; }

    [Inject]
    public IBusinessRepository BusinessRepository
    { set; get; }
}

And during your application startup, you would tell Ninject about these types.

Bind().To().InSingletonScope();
Bind().To().InSingletonScope();