Q141199: FIX: Pop-Up Menu Items Disabled for an OLE Control

Article: Q141199
Product(s): Microsoft C Compiler
Version(s): winnt:4.0,4.1,4.2,5.0
Operating System(s): 
Keyword(s): kbole kbActiveX kbCOMt kbCtrl kbMFC kbVC400 kbVC410 kbVC420 kbVC500 kbVC600fix kbGrpDSM
Last Modified: 09-MAY-2001

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The information in this article applies to:

- Microsoft Visual C++, versions 4.0, 4.1 
- Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2, 5.0 
- Microsoft Visual C++, 32-bit Professional Edition, versions 4.2, 5.0 
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SYMPTOMS
========

The menu items are disabled even though menu handlers were added with Class
Wizard when you create an OLE Control and then use the Pop-up Menu component in
the Component Gallery to add a context menu to the COleControl derived class.
The problem occurs after you modify the context menu, and then add handlers for
the menu items, build the Control, place it in Tstcon32.exe, and bring up the
context menu.

CAUSE
=====

Within the OnContextMenu function added by the Pop-up Menu Component, the code
makes the top-most parent window the parent of the context menu. The menu sends
the WM_COMMAND message to its parent first, which can then route the command
appropriately through the application. This method works for windows in an MFC
application that are part of the command-routing scheme. However, because OLE
Controls are not part of the routing mechanism, the WM_COMMAND message never
gets back to them and therefore the context menu doesn't see the handlers, so
the menu items are disabled.

RESOLUTION
==========

When you add a context menu to an OLE control, you need to make the COleControl
derived class the parent of the context menu. The Pop-up Menu Component creates
the following code within the CWnd derived class. If the pop-up menu is being
added to a COleControl-derived class, you need to delete the following lines of
code:

     while (pWndPopupOwner->GetStyle() & WS_CHILD)
        pWndPopupOwner = pWndPopupOwner->GetParent();

Code Created by Pop-up Menu Component
-------------------------------------

     void CSPLITCtrl::OnContextMenu(CWnd*, CPoint point)
     {
        // CG: This function was added by the Pop-up Menu component

        CMenu menu;
        VERIFY(menu.LoadMenu(CG_IDR_POPUP_SPLITCTRL));

        CMenu* pPopup = menu.GetSubMenu(0);
        ASSERT(pPopup != NULL);

        CWnd* pWndPopupOwner = this;
        while (pWndPopupOwner->GetStyle() & WS_CHILD)
           pWndPopupOwner = pWndPopupOwner->GetParent();

        pPopup->;TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON, point.x,
                               point.y, pWndPopupOwner);
     }

By removing the two lines of code, you are leaving the COleControl-derived class
as the parent of the menu. As a result, the control receives the WM_COMMAND
messages sent by the pop-up menu, so the normal ON_COMMAND functionality added
by Class Wizard worked as designed.

STATUS
======

This problem was corrected in Visual C++ version 6.0 for Windows.

Additional query words:

======================================================================
Keywords          : kbole kbActiveX kbCOMt kbCtrl kbMFC kbVC400 kbVC410 kbVC420 kbVC500 kbVC600fix kbGrpDSMFCATL kbNoUpdate 
Technology        : kbVCsearch kbVC400 kbAudDeveloper kbVC410 kbVC420 kbVC500 kbVC32bitSearch kbVC500Search
Version           : winnt:4.0,4.1,4.2,5.0
Issue type        : kbbug
Solution Type     : kbfix

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