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Q185720: HOWTO: Provide Type Information From an MFC Automation Server

Article: Q185720
Product(s): Microsoft C Compiler
Version(s): winnt:4.0,4.1,4.2,5.0,6.0
Operating System(s): 
Keyword(s): kbole kbnokeyword kbActiveX kbAutomation kbCOMt kbMFC kbVC400 kbVC500 kbVC600 kbGrpDSMF
Last Modified: 17-JUL-2001

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.1 
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 4.2 
   - Microsoft Visual C++, 32-bit Professional Edition, version 4.2 
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
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SUMMARY
=======

This article shows how to provide access to type information from an MFC
automation server at run time. MFC automation servers by default return
E_NOTIMPL for IDispatch::GetTypeInfo().

MORE INFORMATION
================

The automation object in the following steps refers to a CCmdTarget derived
object with automation enabled.

Step-by-Step Example
--------------------

1. Place the DECLARE_OLETYPELIB macro in the automation object's header file
  within the class definition.

2. Place the IMPLEMENT_OLETYPELIB macro in the automation object's
  implementation file at global scope.

3. Override CCmdTarget::GetDispatchIID() in your derived class, and then return
  the IID of the primary dispatch interface.

SAMPLE CODE:

        // In the header file for the automation object, say CmyAutoObject.
        virtual BOOL GetDispatchIID(IID* pIID);

        // In the implementation file for CmyAutoObject.
        BOOL CMyAutoObject::GetDispatchIID(IID* pIID)
        {
           *pIID = IID_IMyAutoObject;
           return TRUE;
        }

4. Call EnableTypeLib(), in the constructor for the automation object.

Make sure that the type library is registered using AfxOleRegisterTypeLib() or
RegisterTypeLib(), or that the type library is available as a resource in the
.dll or .exe file. For more information on how to add the type library as a
resource, please see the following article in the Microsoft Knowledge Base:

  Q122285 HOWTO: Add Type Libraries as Resources to .dll and .exe Files

(c) Microsoft Corporation 1998, All Rights Reserved. Contributions by Jaganathan
Thangavelu, Microsoft Corporation


Additional query words: 0x80004001 [ASCII 150] 2147500033

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Keywords          : kbole kbnokeyword kbActiveX kbAutomation kbCOMt kbMFC kbVC400 kbVC500 kbVC600 kbGrpDSMFCATL 
Technology        : kbAudDeveloper kbMFC
Version           : winnt:4.0,4.1,4.2,5.0,6.0
Issue type        : kbhowto

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