Q152072: FIX: ASSERT in OLECLI1.CPP When Copying Embedding to Clipboard
Article: Q152072
Product(s): Microsoft C Compiler
Version(s): winnt:2.0,2.1,2.2,4.0,4.1; :1.5,1.51,1.52
Operating System(s):
Keyword(s): kbole kbClipboard kbCOMt kbMFC kbVC100bug kbVC150bug kbVC200bug kbVC400bug kbVC500fix k
Last Modified: 04-AUG-2001
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Visual C++, versions 2.0, 2.1, 2.2, 4.0, 4.1
- Microsoft Foundation Classes (MFC)
- Microsoft Visual C++, versions 1.5, 1.51, 1.52
-------------------------------------------------------------------------------
SYMPTOMS
========
When you attempt to copy an embedding in an in-place active object to the
clipboard, the result is an ASSERT in OLECLI1.CPP. Specifically, the ASSERT
occurs in the COleClientItem::XOleClientSite::GetMoniker() function on the
following line of code:
VERIFY(pThis->m_lpObject->SetMoniker(OLEWHICHMK_OBJREL,
*ppMoniker)==S_OK);
CAUSE
=====
When you copy an embedding to the clipboard, a number of data formats are placed
on the clipboard, including link source information. The link source information
contains a moniker used to locate the document in which the embedding resides.
When the container assigns a moniker to an embedded object, it will call the
object's IOleObject::SetMoniker() function. The object will then call the
container's IOleClientSite::GetMoniker() function to construct a composite
moniker based on the container's moniker. This is done because the container may
have changed its moniker while the object was not running.
When the embedded object calls IOleClientSite::GetMoniker() to get the
container's moniker, COleClientItem::XOleClientSite::GetMoniker() ASSERTs on the
aforementioned line of code because pThis->m_bMoniker had not been set to
TRUE when the moniker was assigned during a previous call to
COleClientItem::XOleClientSite::GetMoniker().
The problem is located in the following section of the
COleClientItem::XOleClientSite::GetMoniker() function located in OLECLI1.CPP:
// notify the object of the assignment
if (dwAssign != OLEGETMONIKER_TEMPFORUSER &&
*ppMoniker != NULL && !pThis->m_bMoniker)
{
VERIFY(pThis->m_lpObject->SetMoniker(
OLEWHICHMK_OBJREL, *ppMoniker) == S_OK);
pThis->m_bMoniker = TRUE;
ASSERT_VALID(pThis->;m_pDocument);
pThis->m_pDocument->SetModifiedFlag();
}
The pThis->m_lpObject->SetMoniker() call results in the object calling
COleClientItem::XOleClientSite::GetMoniker() again. Because pThis-
>m_bMoniker is being set after the pThis->m_lpObject->SetMoniker()
call, the subsequent call to pThis->m_lpObject->SetMoniker() returns with
an error code of E_FAIL, triggering the ASSERT.
RESOLUTION
==========
To work around this problem, you must override the default IOleClientSite
interface implementation in COleClientItem. This can be done by adding an
interface map to the class in your project that is derived from COleClientItem
and setting pThis->m_bMoniker to TRUE before calling pThis-
>m_lpObject->SetMoniker() from your custom GetMoniker() function.
The code below illustrates how to override the COleClientItem-derived object
using the OCLIENT MFC sample application.
STATUS
======
Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug was corrected in Visual C++ 32- bit Edtion
version 4.2.
MORE INFORMATION
================
Sample Code
-----------
// Code to be added to CRectItem class definition in RECTITEM.H
class CRectItem : public COleClientItem
{
// ...original declarations in CRectItem class go here...
// Interface Map
BEGIN_INTERFACE_PART(OleClientSite2, IOleClientSite)
STDMETHOD(SaveObject)();
STDMETHOD(GetMoniker)(DWORD, DWORD, LPMONIKER*);
STDMETHOD(GetContainer)(LPOLECONTAINER*);
STDMETHOD(ShowObject)();
STDMETHOD(OnShowWindow)(BOOL);
STDMETHOD(RequestNewObjectLayout)();
END_INTERFACE_PART(OleClientSite2)
DECLARE_INTERFACE_MAP()
};
// XOleClientSite2 functions to be added to RECTITEM.CPP
BEGIN_INTERFACE_MAP(CRectItem, COleClientItem)
INTERFACE_PART(CRectItem, IID_IOleClientSite, OleClientSite2)
END_INTERFACE_MAP()
STDMETHODIMP_(ULONG) CRectItem::XOleClientSite2::AddRef()
{
METHOD_PROLOGUE_EX_(CRectItem, OleClientSite2)
return pThis->ExternalAddRef();
}
STDMETHODIMP_(ULONG) CRectItem::XOleClientSite2::Release()
{
METHOD_PROLOGUE_EX_(CRectItem, OleClientSite2)
return pThis->ExternalRelease();
}
STDMETHODIMP CRectItem::XOleClientSite2::QueryInterface(
REFIID iid, LPVOID* ppvObj)
{
METHOD_PROLOGUE_EX_(CRectItem, OleClientSite2)
return pThis->ExternalQueryInterface(&iid, ppvObj);
}
STDMETHODIMP CRectItem::XOleClientSite2::SaveObject()
{
METHOD_PROLOGUE_EX(CRectItem, OleClientSite2)
ASSERT_VALID(pThis);
return pThis->m_xOleClientSite.SaveObject();
}
STDMETHODIMP CRectItem::XOleClientSite2::GetMoniker(
DWORD dwAssign, DWORD dwWhichMoniker, LPMONIKER* ppMoniker)
{
METHOD_PROLOGUE_EX(CRectItem, OleClientSite2)
ASSERT_VALID(pThis);
USES_CONVERSION; // note, must #include afxpriv.h
COleDocument* pDoc = pThis->GetDocument();
ASSERT_VALID(pDoc);
ASSERT(ppMoniker != NULL);
*ppMoniker = NULL;
switch (dwWhichMoniker)
{
case OLEWHICHMK_CONTAINER:
// return the current moniker for the document
*ppMoniker = pDoc->GetMoniker((OLEGETMONIKER)dwAssign);
break;
case OLEWHICHMK_OBJREL:
{
if (!pDoc->IsKindOf(RUNTIME_CLASS(COleLinkingDoc)))
break;
// don't return relative moniker if no document moniker
LPMONIKER lpMoniker = pDoc-
>GetMoniker((OLEGETMONIKER)dwAssign);
if (lpMoniker == NULL)
break;
lpMoniker->Release();
// relative monikers have to handle assignment correctly
switch (dwAssign)
{
case OLEGETMONIKER_ONLYIFTHERE:
if (!pThis->m_bMoniker)
break; // no moniker assigned, don't return one
// fall through...
case OLEGETMONIKER_TEMPFORUSER:
case OLEGETMONIKER_FORCEASSIGN:
{
// create item moniker from item name
TCHAR szItemName[OLE_MAXITEMNAME];
pThis->GetItemName(szItemName);
CreateItemMoniker(OLESTDDELIMOLE, T2COLE(szItemName),
ppMoniker);
// notify the object of the assignment
if (dwAssign != OLEGETMONIKER_TEMPFORUSER &&
*ppMoniker != NULL && !pThis->m_bMoniker)
{
pThis->m_bMoniker = TRUE;
VERIFY(pThis->m_lpObject->SetMoniker(
OLEWHICHMK_OBJREL, *ppMoniker) == S_OK);
ASSERT_VALID(pThis->m_pDocument);
pThis->m_pDocument->SetModifiedFlag();
}
}
break;
case OLEGETMONIKER_UNASSIGN:
pThis->m_bMoniker = FALSE;
break;
}
}
break;
case OLEWHICHMK_OBJFULL:
{
// get each sub-moniker: item & document
LPMONIKER lpMoniker1, lpMoniker2;
GetMoniker(dwAssign, OLEWHICHMK_CONTAINER, &lpMoniker1);
GetMoniker(dwAssign, OLEWHICHMK_OBJREL, &lpMoniker2);
// create composite moniker
if (lpMoniker1 != NULL && lpMoniker2 != NULL)
::CreateGenericComposite(lpMoniker1, lpMoniker2,
ppMoniker);
// release sub-monikers
RELEASE(lpMoniker1);
RELEASE(lpMoniker2);
}
break;
}
return *ppMoniker != NULL ? S_OK : E_FAIL;
}
STDMETHODIMP CRectItem::XOleClientSite2::GetContainer(LPOLECONTAINER*
ppContainer)
{
#ifdef _DEBUG
METHOD_PROLOGUE_EX(CRectItem, OleClientSite2)
#else
METHOD_PROLOGUE_EX_(CRectItem, OleClientSite2)
#endif
ASSERT_VALID(pThis);
return pThis->m_xOleClientSite.GetContainer(ppContainer);
}
STDMETHODIMP CRectItem::XOleClientSite2::ShowObject()
{
METHOD_PROLOGUE_EX(CRectItem, OleClientSite2)
ASSERT_VALID(pThis);
return pThis->m_xOleClientSite.ShowObject();
}
STDMETHODIMP CRectItem::XOleClientSite2::OnShowWindow(BOOL fShow)
{
METHOD_PROLOGUE_EX(CRectItem, OleClientSite2)
ASSERT_VALID(pThis);
return pThis->m_xOleClientSite.OnShowWindow(fShow);
}
STDMETHODIMP CRectItem::XOleClientSite2::RequestNewObjectLayout()
{
return E_NOTIMPL;
}
Additional query words: 1.50 1.51 1.52 2.00 2.10 2.20 4.00 4.10 4.20 vcfixlist420 MfcOLE
======================================================================
Keywords : kbole kbClipboard kbCOMt kbMFC kbVC100bug kbVC150bug kbVC200bug kbVC400bug kbVC500fix kbVS97 kbGrpDSMFCATL
Technology : kbVCsearch kbVC400 kbAudDeveloper kbMFC kbvc150 kbVC220 kbVC410 kbVC151 kbVC200 kbVC210 kbVC152
Version : winnt:2.0,2.1,2.2,4.0,4.1; :1.5,1.51,1.52
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 1986-2002.