SteveL
10/8/2007 5:49:00 PM
I was told to move my question to this forum:
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I have a C# class which is being called via COM interop from a legacy c++
program compiled under VC7 (VS2003). It worked well before we converted our
C# codebase to VS2005 (.NET 2.0) and now we have the "Class not registered"
result from CoCreateInstance in our C++ code.
The thing is, I can see the GUID in the HKEY_CLASSES_ROOT registry. We
noticed that a new version of RegAsm was supplied with VS2005 (we're up to
date with SP1), and even when we manually register the class library with
RegAsm, (which succeeds) the C++ code can't find the registry entry.
I've checked the GUID and it's identical. Anyone else having this problem?
Here's the C# code wrapper for the COM class:
#region Interface published by your COM class
[Guid("346FFA5F-840C-4728-85AA-F789900F159A"),
InterfaceType(ComInterfaceType.InterfaceIsDual) ]
public interface IOrderEdit
{
[DispId(1)] System.IntPtr RunOrderEditForm ( string dbParams, int
mode, string title, string paramsAsXml );
}
#endregion
[ Guid("DA8FA26B-D07F-40D0-ACB2-40B6665F1A11"),
ProgId("ComUI.OrderEditUI"),
ComVisible(true),
ClassInterface(ClassInterfaceType.None),
ComSourceInterfaces(typeof(IOrderEditUIEvents)) ]
public class OrderEditUI : IOrderEdit
{
// ... class contents skipped for brevity
}
Here's the C++ code that tries to load the COM objects:
IOrderEditPtr spOrdEdit = NULL;
LPOLESTR lpolestr;
StringFromCLSID(__uuidof(OrderEditUI), &lpolestr);
HRESULT hr = spOrdEdit.CreateInstance( __uuidof(OrderEditUI) );
if ( spOrdEdit )
{
// ... stuff we might do if we got this far, deleted for brevity
}
I added the StringFromCLSID to make sure I was looking for the right guid
and I'm looking for this one: DA8FA26B-D07F-40D0-ACB2-40B6665F1A11
I tried running RegMon (SysInternals) and interestingly on the second pass
through the code (first time through it fails with Class not registered as
before), I get an unknown error code in hr = -2146234105 which seems to be
undocumented.
Any help would be very much appreciated...
In the other forum, Alexander Nickolov replied:
> Check if the interface is registered for marshaling. In general, post
> COM Interop questions in the interop group:
> microsoft.public.dotnet.framework.interop
However, as I understand it from Dr. GUI, this would mean registering the
component as both a proxy and a stub, but I don't believe that is necessary
as this is not a remote interface. Note that this all worked when I was
calling a .NET 1.1 class from VC7 C++ code. It is only since I've updated to
the .NET 2.0 framework that I'm having the problem. I did unregister the
class and reregister it to avoid confusion.
Thanks for any help!