Imports CallContext = System.Runtime.Remoting.Messaging.CallContext
Imports ILogicalThreadAffinative = System.Runtime.Remoting.Messaging.ILogicalThreadAffinative


'OUTPUT:
'
'During STA - Hello World!!!
'Setting to 134731742
'After STA - Hello World!!!
'During MTA - Hello World!!!
'Setting to 553887779
'After MTA - Hello World!!!
'Complete



Module Module1

  Private _ewh As New Threading.EventWaitHandle(False, Threading.EventResetMode.AutoReset)

  Sub Main()
    FooContext.SetContext("Hello World!!!")

    Dim threadSTA As New Threading.Thread(AddressOf DoInvoke)
    threadSTA.SetApartmentState(Threading.ApartmentState.STA)
    threadSTA.Start(Function() DoTest("STA", _ewh))
    _ewh.WaitOne()
    Console.WriteLine("After STA - {0}", FooContext.GetFoo)

    Dim threadMTA As New Threading.Thread(AddressOf DoInvoke)
    threadMTA.SetApartmentState(Threading.ApartmentState.MTA)
    threadMTA.Start(Function() DoTest("MTA", _ewh))
    _ewh.WaitOne()
    Console.WriteLine("After MTA - {0}", FooContext.GetFoo)

    Console.WriteLine("Complete")
    Console.ReadKey()
  End Sub

  Private Sub DoInvoke(ByVal del As [Delegate])
    del.DynamicInvoke()
  End Sub

  Private Function DoTest(ByVal msg As String, ByVal ewh As Threading.EventWaitHandle) As Integer
    Dim rnd As Random = New Random
    Dim rndNum As Integer = rnd.Next

    Console.WriteLine("During {0} - {1}", msg, FooContext.GetFoo)
    Console.WriteLine("Setting to {0}", rndNum)

    FooContext.SetContext(rndNum.ToString)

    ewh.Set()
    Return 0
  End Function


  <Serializable()> _
  Public Class FooContext
    Implements ILogicalThreadAffinative

    Private Const CONTEXTKEY As String = "FooContext"

    Public Foo As String

    Public Sub New(ByVal _foo As String)
      Foo = _foo
    End Sub

    Public Shared Sub SetContext(ByVal _foo As String)
      CallContext.SetData(CONTEXTKEY, New FooContext(_foo))
    End Sub

    Public Shared Function GetFoo() As String
      Dim o As Object = CallContext.GetData(CONTEXTKEY)
      If o Is Nothing OrElse Not TypeOf o Is FooContext Then Return "Invalid"
      Return DirectCast(o, FooContext).Foo
    End Function

  End Class

End Module