64位平台上的COM

Question

I'm using a 3rd party COM Library with C#, all works fine on 32 bit XP. I use tlbimp to create the wrapper, add a reference all works. However, when porting to our Server environment which is 64 bit Windows Server 2008, I've run into a road block.

The code below only runs properly when I right click and test it, ie run within the VS environment. The code does not work when compiled to a Console App, nor does the code work in an Assembly whether in test or called from a console App. In an attempt to get it working I'm running as Administrator and in a 32bit command window - still nothing grouper is always null, and no exception is thrown, indicating that GrpSvr.GrpCall is a valid Com Library name.

    string sMessage = "no grouper";
    GrpSvr.GrpCall grouper = Activator.CreateInstance(
        Type.GetTypeFromProgID("GrpSvr.GrpCall")) as GrpSvr.GrpCall;
    if (grouper != null)
        sMessage = grouper.GroupInit(@"C:\CmdGrp.txt", true, true);

    Console.WriteLine(sMessage);

Answer 1

Try using COM+ as host, and keep your application compiled for 64 bits. For more info see this link

Answer 2

It sounds like the 3rd party COM DLL is 32 bits only. You have to configure your app to run as 32 bits only, instead of any cpu.