DOCUMENT:Q192984  07-MAY-2001  [visualc]
TITLE   :PRB: ATL Classes Are Not Compatible With ClassWizard
PRODUCT :Microsoft C Compiler
PROD/VER:WINNT:4.0,4.0a,4.1,4.2,4.2b,5.0,6.0
OPER/SYS:
KEYWORDS:kbwizard kbATL kbMFC kbVC400 kbVC410 kbVC420 kbVC500 kbVC600 kbClassWizard kbGrpDSTools

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-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Visual C++, versions 4.0, 4.0a, 4.1 
 - Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2b, 5.0, 6.0 
 - Microsoft Visual C++, 32-bit Professional Edition, versions 4.2b, 5.0, 6.0 
 - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
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SYMPTOMS
========

The Visual C++ Resource Editor invokes ClassWizard to add message handlers to an
Active Template Library (ATL) dialog resource. However, ClassWizard does not
recognize classes created with the ATL Object Wizard.

CAUSE
=====

ClassWizard works with MFC classes and does not handle ATL classes or message
maps.

RESOLUTION
==========

Add message maps to ATL classes manually. Use ClassView or the WizardBar to add
member functions and variables.

In Visual C++, version 6.0, WizardBar or ClassView can add generic Windows
messages to ATL classes.


STATUS
======

This behavior is by design.

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

When you right-click on an ATL class name in ClassView a context menu appears.
From the context menu, select the Add Member Function option to create the
message handler function. A generic message handler function returns an LRESULT
and has this prototype:

      LRESULT OnMsg(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled);

After adding the message handler function prototype, edit the message map
embedded in the class declaration. Add this macro between the BEGIN_MSG_MAP and
END_MSG_MAP macros:

      MESSAGE_HANDLER(message_id, function_name)

Other message map macros are also available. See REFERENCES for articles
explaining the implementation of ATL window objects.

The following sample declaration of an ATL class implements a dialog box and
handles the WM_CTLCOLORDLG message:

      class CDlg : public CDialogImpl<CDlg>
      {
      public:
      CDlg();
      ~CDlg();

      enum { IDD = IDD_DLG };

      BEGIN_MSG_MAP(CDlg)
         MESSAGE_HANDLER(WM_INITDIALOG, OnInitDialog)
         COMMAND_ID_HANDLER(IDOK, OnOK)
         COMMAND_ID_HANDLER(IDCANCEL, OnCancel)
         MESSAGE_HANDLER(WM_CTLCOLORDLG, OnCtlColorDlg)
      END_MSG_MAP()

      LRESULT OnInitDialog(UINT uMsg, WPARAM wParam, LPARAM lParam,
                         BOOL& bHandled);
      LRESULT OnOK(WORD wNotifyCode, WORD wID, HWND hWndCtl, BOOL& bHandled);
      LRESULT OnCancel(WORD wNotifyCode, WORD wID, HWND hWndCtl,
                         BOOL& bHandled);
      LRESULT OnCtlColorDlg(UINT uMsg, WPARAM wParam, LPARAM lParam,
                         BOOL& bHandled);
      };

Steps to Reproduce Behavior
---------------------------

1. Create a new ATL COM AppWizard, using all default settings.

2. On the Insert menu, click New ATL Object.

3. In the ATL Object Wizard, select the Miscellaneous category, and then
   double-click the Dialog object.

4. Type "Dlg" into the Short Name field; click OK.

5. In the ResourceView pane, expand the project name and Dialog.

6. Double-click IDD_DLG.

7. Double-click inside the displayed dialog box.

RESULTS: The ClassWizard appears, and displays a dialog box titled "Adding a
Class". It offers the option of creating a new class or selecting an existing
class to associate with the IDD_DLG dialog resource. Selecting an existing class
does not list the class created by the ATL Object Wizard.

REFERENCES
==========

For more information on adding MFC support to an ATL project, please see the
following article in the Microsoft Knowledge Base:

   Q181505 PRB: ATL COM AppWizard Doesn't Offer MFC Support for .EXE

For additional information, see the following Help topics:

   Visual C++ Online Help: Developer Products; Visual C++; C/C++ Language and
   C++ Libraries; Active Template Library; Articles; ATL Window Classes;
   Implementing a Window

   Visual C++ Online Help: Developer Products; Visual C++; C/C++ Language and C++
   Libraries; Active Template Library; Articles; ATL Window Classes;
   Implementing a Dialog Box

   Visual C++ Online Help: Developer Products; Visual C++; C/C++ Language and C++
   Libraries; Active Template Library; Class Reference; ATL Macros and Global
   Functions

   Visual C++ 6.0 Online Help: Visual C++ Documentation; Reference; Microsoft
   Foundation Class Library and Templates; Active Template Library; Articles;
   ATL Window Classes; Implementing a Window; Adding a Message Handler

======================================================================
Keywords          : kbwizard kbATL kbMFC kbVC400 kbVC410 kbVC420 kbVC500 kbVC600 kbClassWizard kbGrpDSTools 
Technology        : kbVCsearch kbVC400 kbAudDeveloper kbVC410 kbVC500 kbVC600 kbVC32bitSearch kbVC400a kbVC420b kbVC500Search
Version           : WINNT:4.0,4.0a,4.1,4.2,4.2b,5.0,6.0
Issue type        : kbprb

=============================================================================

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