Question

I am working on asp.net mvc 4. I am trying to implement dependeny injection using ninject and repository pattern with code first model.

IMessageRepository

public interface IMessageRepository
{
void IsMessageRead();
}

MessageRepository

 public class MessageRepository:IMessageRepository
 {
 string id="";
 public MessageRepository(string idparam)
 {
   id=idparam;
 }
 EFMsgContext context=new EFMsgContext(id);
 public void IsMessageRead()
 {
  ...
 }
 }

EFMsgContext

public class EFMsgContext:Dbcontext
{
public EFMsgContext(string id):base("MyContext")
{
 //based on id i will construct a connection string from my database.
}
....
}

my controller

public class MYController:Controller
{
private IMessageRepository repo;
public MYController(IMessageRepository repoparam)
{
repo=repoparam;
}
public ActionResult Index()
{
  repo.IsMessageRead();
}
}

and i am using Ninject for dependency injection i bind my interface with concrete class like,

ninjectKernel.Bind<IMessageRepository>().To<MessageRepository>();

here how could i pass constructor parameters to the binding and is there any way to write the logic for buidling connection string inside the ninjectcontrollerfactory. please guide me.

Answer 1

You have to use the WithConstructorArgument extension method

ninjectKernel.Bind<IMessageRepository>().To<MessageRepository>().WithConstructorArgument("idparam", value);

You can even pass a Func as a second argument.

ninjectKernel.Bind<IMessageRepository>().To<MessageRepository>()
             .WithConstructorArgument("idparam", (c) => {
                   // read from somewhere and return
              });