MEF: Passing different constructor parameters to a part when using CreationPolicy.NonShared

Question

I know there have been lot of questions regarding constructor parameter injection using MEF, but mine is a bit different.

I want to know that is there any way to pass different parameter values to the constructor of a part when I am using the combination of PartCreationPolicy(CreationPolicy.NonShared) and GetExportedValue?

For example:

[PartCreationPolicy(CreationPolicy.NonShared)]
[Export]
public partial class Foo
{
    [ImportingConstructor]
    public Foo([Import("SomeParam")]object parameter)
    {
        ...
    }
}

and somewhere else...

container.ComposeExportedValue("SomeParam", "Some value...");
var instance = container.GetExportedValue<Foo>();

In the above example, I can use ComposeExportedValue only once, as running it a second time will cause a ChangeRejectedException.

So, my questions are:

1. Is there any other way to change the value of SomeParam in the above scenario, for each new instance?
2. If not, what are the other ways this can be accomplished without using any other DI framework? One thing which comes to mind is to create a service to expose something like System.Collections.Concurrent.ConcurrentQueue where I enqueue a parameter value before calling GetExportedValue and then dequeue the value in the constructor of the part. But that is a hack and also creates more issues than it solves.
3. If the answer to both the above questions is no, then are there any other ways to accomplish this with a combination of MEF and some other DI/IOC framework?

Thanks for any help. :)
Regards,
Yogesh Jagota

Answer 1

If the answer to both the above questions is no, then are there any other ways to accomplish this with a combination of MEF and some other DI/IOC framework?

I think the answer to question 1 and 2 is indeed no.

I would try AutoFac which gives you more fine grained control and integrates with MEF. For example, it allows you to set up registrations like this so that Bar and Baz instances get their Foo instance with a different parameter:

builder.Register(c => new Bar(new Foo(param));
builder.Register(c => new Baz(new Foo(param2));