Question

I have the need to check if an instance of some interface has already been created by structuremap. I have tried ObjectFactory.GetInstance() but this creates a new instance of T when called and a concrete instance of T does not exist. I just want to check if an instance of T has already been created (not to create a new). I need this to force the creation of instances through a certain class).

Answer 1

You cannot ask StructureMap if it has already created an instance of an interface.

However, it does have many lifecycle management features that allow it to control whether it creates a new instance, or returns a cached instance that it previously created.

You can tell StructureMap to make an instance HttpContextScoped, so that it returns the same instance for a given HTTP request.

It sounds like what you really want to know is how to handle NHibernate sessions in a web application with StructureMap. Try:
http://trason.net/journal/2009/10/7/bootstrapping-nhibernate-with-structuremap.html