PRB: MFC Classes Removed from OLE CDK Runtime DLLs

• Microsoft OLE Control Development Kit (CDK), version 1.0

SYMPTOMS

The OLE control runtime DLLs contain a subset of the full MFC library. If you attempt to instantiate a class that is unavailable, the compiler will generate the following (or similar) error messages:

   error C2501: 'CRecordSet' : missing decl-specifiers
   error C2239: unexpected token 'identifier' following declaration of
      'CRecordSet'
   error C2061: syntax error : identifier 'recordset'

CAUSE

The errors occur because preprocessor directives are used to remove several MFC class definitions from the MFC header files when building an OLE control.

RESOLUTION

You can prevent these errors from occuring by simply not declaring any instances of classes listed in the More Information section. The classes are not available for OLE controls.

STATUS

This behavior is by design.

MORE INFORMATION

The following lists the general-purpose MFC classes that are unavailable for OLE controls:

CDocTemplate CDocItem CMDIFrameWnd CMDIChildWnd CMultipleDocTemplate CDocTemplate COleBusyDialog COleChangeIconDialog COleClientItem COleConvertDialog COleDialog COleDocument COleFrameHook COleInsertDialog COleIPFrameWnd COleLinkingDoc COleLinksDialog COleMessageFilter COlePasteSpecialDialog COleServerDoc COleServerItem COleTemplateServer COleUpdateDialog

Also, all MFC database classes are unavailable in version 1.0 of the CDK, including:

CDatabase CRecordSet CRecordView CLongBinary CFieldExchange CDBException

NOTE: The database classes are now included in version 1.1 of the CDK.