DOCUMENT:Q167697 17-JUL-2001 [visualc] TITLE :FIX: ActiveX Control in IE Asserts in CTLINPLC.CPP, Line 328 PRODUCT :Microsoft C Compiler PROD/VER:winnt:4.0,4.0a,4.1,4.2,4.2b,5.0 OPER/SYS: KEYWORDS:kberrmsg kbole kbActiveX kbCOMt kbCtrl kbCtrlCreate kbIE300 kbIE301 kbMFC kbVC400bug kb ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - The Microsoft Foundation Classes (MFC), used with: - Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.0a, 4.1, 4.2b - Microsoft Visual C++, 32-bit Enterprise Edition, version 4.2 - Microsoft Visual C++, 32-bit Professional Edition, version 4.2 - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 - Microsoft Internet Explorer (Programming) versions 3.0, 3.01, 3.02 ------------------------------------------------------------------------------- SYMPTOMS ======== Clicking on an MFC ActiveX control that is hosted in a frame in Internet Explorer may cause an assert in CTLINPLC.CPP, line 328. CAUSE ===== The assert is in COleControl::BuildSharedMenu(), where it checks: if (m_pUIActiveInfo != NULL) { ASSERT(m_pUIActiveInfo->m_hSharedMenu != NULL); return TRUE; } m_pUIActiveInfo->m_hSharedMenu will always be NULL because you are not doing menu merging. m_pUIActiveInfo is set to NULL when the control is UI de-activated. In this case, the control is inplace activated when you first click on it, so COleControl::OnActivateInPlace() is called. This, in turn, calls BuildSharedMenu(). When BuildSharedMenu() returns, but before OnActivateInPlace() is exited, Internet Explorer calls DoVerb(OLEIVERB_UIACTIVATE) on the control. This causes OnActivateInPlace() to be re-entered and BuildSharedMenu() to be called again. Because the control has not been UI-de-activated, m_pUIActiveInfo is not NULL. RESOLUTION ========== You need to prevent OnActivateInPlace() from being re-entered by overriding OnActivateInPlace() and setting a static boolean flag to determine if it has been re-entered. If that is the case, then return the following: " HRESULT CTestCtrl::OnActivateInPlace(BOOL bUIActivate, LPMSG pMsg) { static BOOL bInsideFunc = FALSE; if (!bInsideFunc) { bInsideFunc = TRUE; HRESULT hr = COleControl::OnActivateInPlace(bUIActivate, pMsg); bInsideFunc = FALSE; return hr; } return S_OK; } " (without the quotation marks) STATUS ====== Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem was corrected in Visual C++ version 6.0 for Windows. MORE INFORMATION ================ Steps to Reproduce Behavior --------------------------- 1. Put an MFC ActiveX control in a frame in Internet Explorer. 2. Click on the control. 3. Click on a different frame. 4. Click back on the control. Additional query words: ====================================================================== Keywords : kberrmsg kbole kbActiveX kbCOMt kbCtrl kbCtrlCreate kbIE300 kbIE301 kbMFC kbVC400bug kbVC410bug kbVC420bug kbVC500bug kbVC600fix kbIE302 kbGrpDSMFCATL kbNoUpdate Technology : kbAudDeveloper kbMFC Version : winnt:4.0,4.0a,4.1,4.2,4.2b,5.0 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.