EF code first attach and create proxy

Question

Let's say I have an entity Foo.

public class Foo
{
  public int Id {get;set;}
  public virtual ICollection<Bar> Bars {get;set;}
}

When I get this entity from the db then I actually get a proxy and everything works as it should be.

But, can I attach Foo to DbContext and create the proxy manually so Bars would not return null after attaching it, but an actual collection of bars?

Meaning

var foo = new Foo { Id = 1 };
Context.Set<Foo>().Attach(foo);
foo = CreateProxyOf(foo);
var countOfBars = foo.Bars.Count();

Is there something like CreateProxyOf?

Ladislav Mrnka Ladislav Mrnka · Accepted Answer · 2011-05-17T11:50:11

Yes there is a way but instead of Foo's constructor you must use:

var set = Context.Set<Foo>();
var foo = set.Create();
foo.Id = 1;
set.Attach(foo);
var countOfBars = foo.Bars.Count();