BUG: ATL Object Wizard Doesn't Add Entry to Connection Point Map

• The Microsoft Active Template Library (ATL) 3.0, used with:
  • Microsoft Visual C++, 32-bit Editions, version 6.0

SYMPTOMS

IConnectionPointContainer::FindConnectionPoint() might fail with the following error:

CONNECT_E_NOCONNECTION (0x80040200 - there is no connection for this
connection id)

CAUSE

The ATL Object Wizard has an option to add connection point support to your COM object. This enables connection points for your COM object by deriving your object's class from IConnectionPointContainerImpl, adding a connection point map (BEGIN_CONNECTION_POINT_MAP / END_CONNECTION_POINT_MAP), and adding an event interface (dispinterface) definition to the .idl file and making it the default source interface for the COM object. However, the wizard does not add the event interface to the connection point map.

RESOLUTION

Add the CONNECTION_POINT_ENTRY to the connection point map manually. Prefix DIID_ to the event interface name to generate the IID for the entry. For example:

   BEGIN_CONNECTION_POINT_MAP(CFoo)
      CONNECTION_POINT_ENTRY(DIID__DMyEvent)
   END_CONNECTION_POINT_MAP() 

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a default ATL AppWizard EXE or DLL project.



2. Add an object using the ATL Object Wizard. (Choose New ATL Object from the Insert menu). Select any one of the different COM object types. On the Attributes tab of the ATL Object Wizard, select the Support Connection Points box.



3. In the <projectname>.idl file, you can see that in addition to the object's interface, there is an event interface which is the default source interface in the coclass of this object.



4. In the header file for the object class, you can see that the object class is derived from IConnectionPointContainerImpl, and there is a connection point map. Note that there is not a connection point entry for the event interface.

© Microsoft Corporation 1998, All Rights Reserved.
Contributions by Jaganathan Thangavelu, Microsoft Corporation

Additional query words: IConnectionPointContainer IConnectionPoint

Keywords : kberrmsg kbwizard kbActiveX kbCOMt kbConnPts kbVC600bug kbATL300bug kbGrpMFCATL
Version : WINDOWS:3.0
Platform : WINDOWS
Issue type : kbbug