DOCUMENT:Q184820  28-JUN-2001  [visualc]
TITLE   :FIX: Apply Button on an ATL Control's Property Page Is Disabled
PRODUCT :Microsoft C Compiler
PROD/VER:WINDOWS:2.0,2.1
OPER/SYS:
KEYWORDS:kbnokeyword kbActiveX kbATL200bug kbATL210bug kbCOMt kbContainer kbCtrl kbPropSheet kbV

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

 - The Microsoft Active Template Library (ATL), versions 2.0, 2.1, used with:
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 4.2b 
    - Microsoft Visual C++, 32-bit Professional Edition, version 4.2b 
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
    - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

When embedding an ATL ActiveX control inside a container application written in
Visual Basic (VB), the Apply button on the control's property page is never
activated even though the property page's dirty flag is set [that is, calling
SetDirty(TRUE)] to enable the button.

CAUSE
=====

Below is the SetDirty() function copied from the Atlctl.h file:

      void SetDirty(BOOL bDirty)
      {
         T* pT = static_cast<T*>(this);
         if (!pT->m_bDirty && bDirty)
            pT->m_pPageSite->OnStatusChange(
               PROPPAGESTATUS_DIRTY | PROPPAGESTATUS_VALIDATE);
         pT->m_bDirty = bDirty;
      }

When OnStatusChange() is called, Visual Basic in turn calls IsPageDirty(), which
returns S_OK if m_bDirty is set to TRUE; otherwise, S_FALSE.

However, as shown above, m_bDirty is not set until OnStatusChanged() returns.

RESOLUTION
==========

Please note that m_bDirty must be set before OnStatusChanged() is called in
SetDirty().

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This problem was corrected ATL version 3.0, which
shipped with Visual C++ version 6.0 for Windows.

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

The following are two workarounds:

1. Add an additional call to OnStatusChanged() right after SetDirty() is called.
   Using the ATL Polygon sample code, the change is shown below: "

         LRESULT OnSidesChange(WORD wNotify, WORD wID, HWND hWnd, BOOL&
            bHandled)
         {
            SetDirty(TRUE);
            m_pPageSite->OnStatusChange(
               PROPPAGESTATUS_DIRTY | PROPPAGESTATUS_VALIDATE);
            return 0;
         }

   " (without the quotation marks)

2. Change the SetDirty() function in Atlctl.h to the following: "

         void SetDirty(BOOL bDirty)
         {
            T* pT = static_cast<T*>(this);
            if (pT->m_bDirty != bDirty)
            {
               pT-.m_bDirty = bDirty;
               if (bDirty)
                  pT->m_pPageSite->OnStatusChange(
                     PROPPAGESTATUS_DIRTY | PROPPAGESTATUS_VALIDATE);
            }
         }

   " (without the quotation marks)

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

1. Place an ATL Polygon control on a Visual Basic Form.

2. Display the Polygon control's Property Pages dialog box by selecting the
   (Custom) property from Visual Basic's Properties window.

   NOTE: The Apply button on the Property Pages window is initially disabled.

3. Enter an integer value in the Sides edit box.

   NOTE: The Apply button remains disabled.

(c) Microsoft Corporation 1998, All Rights Reserved. Contributions by Yeong- Kah
Tam, Microsoft Corporation

Additional query words: ocx

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Keywords          : kbnokeyword kbActiveX kbATL200bug kbATL210bug kbCOMt kbContainer kbCtrl kbPropSheet kbVBp kbVC420bug kbVC500bug kbVC600fix kbATL300fix kbGrpDSMFCATL 
Technology        : kbVCsearch kbAudDeveloper kbATLsearch
Version           : WINDOWS:2.0,2.1
Issue type        : kbbug
Solution Type     : kbfix

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

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