COM<->Remoting(Client Side)<->(Server Side)Remoting<->COM E_NOINTERFACE

[Timeshell]

So, here it is. Basically, I have a VB5 client/server app that communicates via DCOM. Because of the horrendous times we have been having keeping it working, I have finally decided it was time to start phasing the DCOM out. The very first step to do this needs to be to create a .NET Remoting/WCF bridge between the client and server.

I have linked the server.com to the server.Remote and the client.remote is able to communicate with with com objects passed through the Remoting bridge. The problem lies in exposing the class that obtains the server.com objects back to the COM client. The same code that works within the Client.Remoting is unable to pass the same object one step further to the client.com when client.com asks for it. The error is E_NOINTERFACE. I am at a complete loss as why this is. Other methods on client.Remoting exposed over the same COM interface do work. So it seems somehow that an interface required to connect the object from server.com between client.Remoting and client.com is either broken or missing. The interface is in the references for all projects passing it along the way. And as indicated, it appears that the variables and methods are making it at least as far as the client.Remoting from the server.com.

I have also tried passing a variable bored through a function call to get the data all the way through with the same result. I have thought about trying to do a delegate/callback/addressof type thing to see if I can just pass back a pointer to it but I really don't like that idea.

I'm wondering if there is a marshalling issue or if I'm missing a reference or need to manually define an interface. I'm hoping someone can give me a better direction to go in.

I'm hoping this will make sense to someone before I paste any code in.

Client/Server VB5
Server COM EXE
Vb.NET Express 2013

[Timeshell]

Remote Server Side Interface:

    Public Interface IRemotingServer
        Function GetNewCOMObj() As VB6ComServer.ActiveX-EXE.ClassVB6ComServer
    End Interface

Remoting Server side code:

Imports VB6ComServer.ActiveX-EXE   'ActiveX Exe COM Server


    Public Class RemotingServer
        Inherits MarshalByRefObject
        Implements IRemotingServer


        Public mgr As VB6ComServer.ActiveX-EXE.ClassVB6ComServer

        Function GetNewCOMObj() As VB6ComServer.ActiveX-EXE.ClassVB6ComServer Implements IRemotingServer.GetNewCOMObj

            Dim mgr As New VB6ComServer.ActiveX-EXE.ClassVB6ComServer

            Return mgr

    End Class

Remoting Server Remoting code:

            Dim ServiceChannel As IChannel
            Dim serverProv As BinaryServerFormatterSinkProvider = New BinaryServerFormatterSinkProvider
            Dim clientProv As BinaryClientFormatterSinkProvider = New BinaryClientFormatterSinkProvider
            Dim Props As IDictionary = New Hashtable
            Dim IpInjProvider As New IpInjectorSinkProvider

            serverProv.TypeFilterLevel = System.Runtime.Serialization.Formatters.TypeFilterLevel.Full
            Props("port") = "8000"
            Props("name") = "RemoteServer.rem"
            serverProv.Next = IpInjProvider

            ServiceChannel = New TcpChannel(Props, clientProv, serverProv)
            '---------------------------------------------

            ChannelServices.RegisterChannel(ServiceChannel)

            RemotingConfiguration.RegisterWellKnownServiceType( _
                  GetType(VB6ComServer.ActiveX-EXE.ClassVB6ComServer), _
                  "RemoteServer.rem", WellKnownObjectMode.Singleton)

Remoting Client Side Code:

Imports System.Runtime.InteropServices
Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
Imports System.Runtime.Remoting.Channels.Tcp
Imports System.Net
Imports System.ServiceModel
Imports System.Configuration

    <Guid("6CC8BE47-2552-4832-8924-21C67A5EAFEB"), _
InterfaceType(ComInterfaceType.InterfaceIsIDispatch)> _
    Public Interface _clsManager_Client
        <DispId(1)> Function GetMonth() As Integer
        <DispId(2)> Function GetDay() As Integer
        <DispId(3)> Function GetYear() As Integer
        <DispId(4)> Function GetNewManager() As VB6ComServer.ActiveX-EXE.ClassVB6ComServer

    End Interface


    <Guid("3d9e2e6f-5bf2-f14f-879b-4e5b0af104e9"), _
    ClassInterface(ClassInterfaceType.AutoDual), _
    ProgId("comDemo.demo")> _
    Public Class clsManager_Client
        Implements _clsManager_Client
	
        Public Function GetMonth() As Integer Implements _clsManager_Client.GetMonth
            GetMonth = DateTime.Now.Month
        End Function

        Public Function GetDay() As Integer Implements _clsManager_Client.GetDay
            GetDay = DateTime.Now.Day
        End Function

        Public Function GetYear() As Integer Implements _clsManager_Client.GetYear
            GetYear = DateTime.Now.Year
        End Function

        Public obj As New clsPrivateManager

        Public Function GetNewManager() As VB6ComServer.ActiveX-EXE.ClassVB6ComServer Implements _clsManager_Client.GetNewManager
            Dim thing As IRemotingServer
            thing = obj.CreateProxyInstance

            Dim mgr As VB6ComServer.ActiveX-EXE.ClassVB6ComServer
            mgr = thing.GetNewManager
            MsgBox("getting manager")

            Return mgr
        End Function


        Public Sub New()
            MyBase.New()
        End Sub

        Public Enum CommunicationPlatform
            Remoting
        End Enum
        Public defaultPlatform As CommunicationPlatform
        Public ReadOnly Property Platform As CommunicationPlatform
            Get
                Return defaultPlatform
            End Get
        End Property

        Public factory As ChannelFactory(Of IRemotingServer) = Nothing

        Public Sub ClientProxyFactory()

            RemotingConfiguration.Configure("app.config", False)
            defaultPlatform = [Enum].Parse(GetType(CommunicationPlatform), _
                                           ConfigurationManager.AppSettings("communicationPlatform"))
        End Sub

        Public Function CreateProxyInstance() As IRemotingServer
            Return CreateProxyInstance(defaultPlatform)
        End Function

        Public Function CreateProxyInstance(platform As CommunicationPlatform) As IRemotingServer
            Dim proxy As IRemotingServer
            proxy = Nothing

            Select Case platform
                Case CommunicationPlatform.Remoting
                    proxy = CType(Activator.GetObject(GetType(IRemotingServer), "tcp://localhost:8000/RemoteServer.rem"), IRemotingServer)
            End Select

            Return proxy
        End Function


        Private chan As TcpChannel
        Public mgr As IRemotingServer

        Private varIdling As Integer

        Public Property Idling As Integer
            Get
                Return varIdling
            End Get
            Set(value As Integer)
                varIdling = value
            End Set
        End Property

        Public Sub New()
            MyBase.New()

            On Error Resume Next

            Idling = 15
        End Sub
    End Class

COM Client Code:

Private mgr As VB6ComServer.ActiveX-EXE.ClassVB6ComServer
Private mgrs As New RemotingClient.clsManager_Client

Private Sub CreateManager()
	Dim i As Integer
	'Dim mgr As New cVB6ComServer.ActiveX-EXE.ClassVB6ComServer


	i = mgrs.GetDay				'  <-- THESE WORK
	i = mgrs.GetMonth
	i = mgrs.GetYear



	mgr = mgrs.GetNewManager	'	<-- THIS DOESN'T WORK.  I get E_NOINTERFACE


End Sub

[Schmidt]

In case I'm not too late with offering help - and you're still interested...

Could you post the Interface of the old Serverside Class -> ClassVB6COMServer?
(if possible as VBClassic-Code, meaning only the Public Method-Signatures)

Basically I just want to look at the Types of the Arguments and ReturnValues,
of those Methods, whether there's something "special" in them.

And alongside the above request - was the serverside Class:
ClassVB6COMServer
...your only interface which got "remoted" over DCOM, or were there more
serverside Classes?

If it's the only Interface (the only serverside Class)... was it indeed used as a Singleton
(as some stuff in your posted snippets suggested) - meaning, was it used to
"share state" among connecting Clients, or was this Class internally implemented
as being "stateless"?

Olaf