CODEWITHSUNDEEP
c#linqasp.net-web-apidependency-injectionunity-container
MarceloBarbosa
MarceloBarbosa

Reputation: 915

Web API + Unity - Reference object dbcontext already instantiated

I'm using Unity for dependency injection.

I have a method responsible to instantiate the Database Object as follow:

        container.RegisterType<DB>(
            new InjectionFactory(c =>
            {
                return new DB();
            })
        );

The problem is, I have a method that use two different objects that are suposed to be referenced to the same DB instance, but look's like Unity are creating a new instance of DB Object in each injection.

Query LINQ example:

var test = from tb1 in _db1.method()
           join tb2 in _db2.method() on tb1.code equals tb2.code

_db1 and _db2 reference the same DB Object as follow

    DB _db = null;

    public db1(DB dataContext)
    {
        _db = dataContext;
        _db.CommandTimeout = 3600;
    }

So i'm getting the following error:

The query contains references to items defined on a different data context

Could some one help me fix Unity register to reference the DB Object already instantiated instead do a new every time?

Upvotes: 0

Views: 241

Answers (1)

Robbert Draaisma
Robbert Draaisma

Reputation: 463

You should register your db as a singleton in the container, that means each time the db is requested the same instance is returned, this:

container.RegisterType<DB>(new ContainerControlledLifetimeManager())

should do it, if this is a web application you should probably create a child container for each request there are different ways to do this, but you might want to give https://www.nuget.org/packages/Unity.Mvc4/ a try

Upvotes: 1

Related Questions