SerializationException when raising event in other instance via IPC

Question

I'm trying to send some information from a newly launched instance of my application to the currently running instance (namely one argument in the form of a string) by way of ipc.

Class RemoteObject
    Inherits MarshalByRefObject
    Public Event ParamEvent As RemoteObject.ParamEventHandler
    Public Property path As String = ""
    Delegate Sub ParamEventHandler()
    Public Sub FireEvent()
        RaiseEvent ParamEvent()
    End Sub
End Class

Friend WithEvents on MainWindow:

 Friend WithEvents theRemoteObject As RemoteObject

I'm setting it up in my first instance like this.

theRemoteObject = New RemoteObject
theRemoteObject.path = "blah"
theChannel = New IpcChannel("localhost:9090")
ChannelServices.RegisterChannel(theChannel, False)
RemotingServices.Marshal(theRemoteObject, "ParamReceiver")

And in my second instance:

Dim uri As String = "ipc://localhost:9090/ParamReceiver"
theChannel = New IpcChannel
ChannelServices.RegisterChannel(theChannel, False)
theRemoteObject = DirectCast(RemotingServices.Connect(GetType(RemoteObject), uri), RemoteObject)
theRemoteObject.path = "blarg"
theRemoteObject.FireEvent()

Everything works properly; when the second instance starts the path property changes from "blah" to "blarg" in both instances. However, when I add this event handler in MainWindow:

Public Sub ParamHandler() Handles theRemoteObject.ParamEvent
    'do stuff here
End Sub

It halts on this line in the second instance:

theRemoteObject = DirectCast(RemotingServices.Connect(GetType(RemoteObject), uri), RemoteObject)

With the following exception:

An exception of type 'System.Runtime.Serialization.SerializationException' occurred in mscorlib.dll but was not handled in user code

Additional information: Type 'Cutlist3.MainWindow' in Assembly 'Cutlist3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' is not marked as serializable.

I don't know what this means or where to start in debugging it. Any information you could provide would be super helpful and appreciated!

Answer 1

For future reference, I solved my problem by creating a new object declaration in the second instance Dim SecondObject as RemoteObject = DirectCast ... instead of using the original Friend WithEvents theRemoteObject declaration.