HOWTO: Raise C# event and handle in VBScript

The event SomeEvent() is raised and handled in VB6 fine. Using this exact
same code and using VBScript with the CreateObject call causes an error in
the c# code.

When using VBScript, I get a 'Object reference not set to an instance of an
object.' on the line SomeEvent(). I am positive the m_nSomeProperty =
nValue; line executes.

How can I get this working from VBScript?


Here's the code:
using System;

using System.Runtime.InteropServices;

namespace ComInterop
{
public delegate void SomeEventHandler();

[ Guid("F8E81A5A-BB37-49CC-9681-7D4FE52936B3"),
InterfaceType(ComInterfaceType.InterfaceIsIDispatch) ]
public interface ICComInteropEvents
{
[DispId(1)] void SomeEvent();
}

[ Guid("97C8501B-35DE-48CA-BECC-B980D08226F4"),
InterfaceType(ComInterfaceType.InterfaceIsDual) ]
public interface ICComInterop
{
[DispId(2)] void SomeMethod( int nValue );
[DispId(3)] int SomeProperty{ get; set; }
}

[ Guid("10EBC493-D2FD-4723-9F8B-F593586ED9B7"),
ProgId("ComInterop.CComInterop"),
ClassInterface(ClassInterfaceType.None),
ComSourceInterfaces(typeof(ICComInteropEvents)) ]
public class CComInterop : ICComInterop
{
public CComInterop() : base()
{
}

private int m_nSomeProperty = 0;
public event SomeEventHandler SomeEvent;

public void SomeMethod( int nValue )
{
m_nSomeProperty = nValue;
///////////////////////////////////////////////////////////////////////////////////////////
//
// object reference not set to an object error occurs here
//
//////////////////////////////////////////////////////////////////////////////////////////
SomeEvent();
}

public int SomeProperty
{
get{ return m_nSomeProperty; }
set{ m_nSomeProperty = value; }
}
}
}



And the VBScript code:

Option Explicit
' ==========================================================================
' Implementation
'
' ==========================================================================

Dim objReceive
Dim bDone

On error Resume Next

bDone = false
WScript.Echo "CreateObject"
Set objReceive = CreateObject("ComInterop.CComInterop")
if Err.Number <> 0 then
WScript.Echo "Error: CreateObject: " & Err.Description
else
objReceive.SomeMethod(7)
if Err.Number <> 0 then
WScript.Echo "Error: Setting SomeMethod: " & Err.Description
else
WScript.Sleep 3000
end if

end if

objReceive = nothing

WScript.Echo "Program Over"
' ==========================================================================

Sub objReceive_SomeEvent()
WScript.Echo "Message: " & objReceive.SomeProperty
bDone = true
End Sub



--
Dan Sikorsky, MSCS BSCE BAB