MEF CompositionContainer Missing ComposeParts Extension method

Question

I am trying to abstract away the MEF composition of parts into a class library class but I am having problems in .Net4.5 RC as the ComposeParts Extension method is not available in the class library CompositionContainer

Am I doing something wrong or perhaps missing a reference?

WCF Service Class Working Container

<Import(GetType(IGenericModelFactory))>
Public Property ModelFactory As IGenericModelFactory

Private _mefContainer As CompositionContainer
Private _catelog As DirectoryCatalog

Public Sub New()
    _catelog = New DirectoryCatalog(".")
    _mefContainer = New CompositionContainer(_catelog)
    _mefContainer.ComposeParts(Me)
End Sub

Class Library - Missing ComposeParts method

Imports System.ComponentModel.Composition.Hosting

Namespace Core.Composition

    Public Class CompositionBuilder
        Implements IComposeObjects

        Public Function CreateContainer() As CompositionContainer Implements IComposeObjects.CreateContainer
            Return Activator.CreateInstance(Of CompositionContainer)()
        End Function

        Public Sub ComposeFromDirectory(directory As String, compositionRoot As Object) Implements IComposeObjects.ComposeFromDirectory

            Dim catelog As DirectoryCatalog = Activator.CreateInstance(GetType(DirectoryCatalog), directory)
            Dim mefContainer As CompositionContainer = Activator.CreateInstance(GetType(CompositionContainer), catelog)
            mefContainer.Composeparts(compositionRoot)

        End Sub

    End Class

End Namespace

Answer 1

Looks like you have to include the System.ComponentModel.Composition namespace

Imports System.ComponentModel.Composition.Hosting
Imports System.ComponentModel.Composition

Namespace Core.Composition

    Public Class CompositionBuilder
        Implements IComposeObjects

        Public Function CreateContainer() As CompositionContainer Implements IComposeObjects.CreateContainer
            Return Activator.CreateInstance(Of CompositionContainer)()
        End Function

        Public Sub ComposeFromDirectory(directory As String, compositionRoot As Object) Implements IComposeObjects.ComposeFromDirectory

            Dim catelog As DirectoryCatalog = Activator.CreateInstance(GetType(DirectoryCatalog), directory)
            Dim mefContainer As CompositionContainer = Activator.CreateInstance(GetType(CompositionContainer), catelog)
            mefContainer.ComposeParts(compositionRoot)

        End Sub

    End Class

End Namespace