Com Interop w/ MSXML

Question

I'm trying to COM interop w/ Navision through a .Net assembly - and specifically using MSXML interfaces. This leads to the following error message:

The assembly "C:\Users\bra\Documents\Visual Studio 2008\Projects\SOAPROXY\SOAPROXY\bin\Release\SOAPROXY.dll" could not be converted to a type library. Type library exporter encountered an error while processing 'SOAPROXY.ISoap.PostEnvelope(#0), SOAPROXY'. Error: Type library exporter cannot load type 'MSXML2.IXMLDOMDocument' (error: System.IO.FileNotFoundException: Could not load file or assembly 'Interop.MSXML2, Version=6.0.0.0, Culture=neutral, PublicKeyToken=fbdb4bb4a7dccef2' or one of its dependencies. The system cannot find the file specified. File name: 'Interop.MSXML2, Version=6.0.0.0, Culture=neutral, PublicKeyToken=fbdb4bb4a7dccef2'). SOAPROXY

The basic interface is defined as

[Guid("some guid")]
[ComVisible(true)]
public interface ISoap
{
    IStatus State { get; }

    IXMLDOMDocument PostEnvelope(IXMLDOMDocument envelope, string action, string endpoint, string print, string store, string location);
}

[ClassInterface(ClassInterfaceType.None)]
[ComVisible(true)]
public class Soap : ISoap
{
     ...
}

Any clues?

Your username is bra? how cool is that? Do you know anyone called Pieter Antiessen? — Patrick McDonald
That's my email prefix @ work. Nope don't know that dude. I know bra is good in Swedish ;-) Wonder-bra and what have you! — Bent Rasmussen
Perhaps this MSDN article may be of use, it describes NAV/COM interop. — Alex Peck

Cheeso Cheeso · Accepted Answer · 2009-05-29T16:53:51

Have you GAC'd the Interop wrapper on MSXML6 ? Seems like Fusion is failing to load the Assembly, and to solve that you would just GAC it. Or put it on the Fusion load path.

But I don't see why you need MSXML in order to make a request to a SOAP Web service. Why not just use the WebClient ad XmlDocument that is builtin to .NET BCL?

I am assuming from what you wrote above that you want to build a Navision "extension" (maybe not the right word) to connect to an external web service, that speaks XML or maybe more specifically, SOAP. And also assuming that you can build a Navision extension in .NET, but that you cannot use wsdl.exe or svcutil.exe, the tools for the 2 web services stacks built-in to .NET. If that is true, why not use the lower-level HTTP and XML classes that are available in .NET?

You wouldn't need COM interop at all.

Com Interop w/ MSXML

2 Answers