ID: Q177551
The information in this article applies to:
- Microsoft Visual C++, 32-bit Editions, versions 4.2, 4.2b, 5.0
When you load a file into Internet Explorer 4.0 (IE4) that is associated with an Active Document server that is written in MFC, you cannot navigate away from the currently loaded page. IE4 will appear to start loading the next page, the progress bar indicator will fill part way, and the IE logo will begin spinning. However, IE4 will remain in this state indefinitely, until shut down.
This is caused by a fault in MFC's implementation of IOleCommandTarget::QueryStatus. MFC's QueryStatus implementation incorrectly specifies that unknown command IDs are currently supported but disabled. Internet Explorer 4.0 uses an unsupported command-group command to determine whether the Active Document (formerly called "ActiveX Document") server can be deactivated. Since MFC responds incorrectly that the command-group command is supported and disabled, the Active Document server is never unloaded.
As a workaround, you must override CDocObjectServer and COleCmdUI to provide the correct functionality. (See the MORE INFORMATION section for instructions on how to do this.)
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.
The following information describes the steps to work around the bug that is stated above. The AxDocFix sample referenced below demonstrates this workaround.
To work around this bug, follow these steps for a basic AppWizard-created Active Document server:
1. Override CDocObjectServer: create a new class CMyDocObjectServer and
derive it publicly from CDocObjectServer. Provide a constructor as
follows:
class CMyDocObjectServer : public CDocObjectServer
{
public:
CMyDocObjectServer(COleServerDoc* pOwner,
LPOLEDOCUMENTSITE pDocSite = NULL)
: CDocObjectServer(pOwner, pDocSite) {}
}
CMyDocObjectServer.
DECLARE_INTERFACE_MAP()
BEGIN_INTERFACE_PART(MyOleCommandTarget, IOleCommandTarget)
STDMETHOD(QueryStatus)(const GUID*, ULONG, OLECMD[], OLECMDTEXT*);
STDMETHOD(Exec)(const GUID*, DWORD, DWORD, VARIANTARG*,
VARIANTARG*);
END_INTERFACE_PART(MyOleCommandTarget)
CMyDocObjectServer.
BEGIN_INTERFACE_MAP(CMyDocObjectServer, CDocObjectServer)
INTERFACE_PART(CMyDocObjectServer, IID_IOleCommandTarget,
MyOleCommandTarget)
END_INTERFACE_MAP()
QueryInterface(), and Exec().
STDMETHODIMP_(ULONG)
CMyDocObjectServer::XMyOleCommandTarget::AddRef()
{
METHOD_PROLOGUE_EX(CMyDocObjectServer, MyOleCommandTarget)
ASSERT_VALID(pThis);
return pThis->m_xOleCommandTarget.AddRef();
}
STDMETHODIMP_(ULONG)
CMyDocObjectServer::XMyOleCommandTarget::Release()
{
METHOD_PROLOGUE_EX(CMyDocObjectServer, MyOleCommandTarget)
ASSERT_VALID(pThis);
return pThis->m_xOleCommandTarget.Release();
}
STDMETHODIMP CMyDocObjectServer::XMyOleCommandTarget::QueryInterface(
REFIID iid, LPVOID* ppvObj)
{
METHOD_PROLOGUE_EX(CMyDocObjectServer, MyOleCommandTarget)
ASSERT_VALID(pThis);
return pThis->m_pOwner->ExternalQueryInterface(&iid, ppvObj);
}
STDMETHODIMP CMyDocObjectServer::XMyOleCommandTarget::Exec(
const GUID* pguidCmdGroup, DWORD nCmdID, DWORD nCmdExecOpt,
VARIANTARG* pvarargIn, VARIANTARG* pvarargOut)
{
METHOD_PROLOGUE_EX(CMyDocObjectServer, MyOleCommandTarget)
ASSERT_VALID(pThis);
return pThis->m_xOleCommandTarget.Exec(pguidCmdGroup, nCmdID,
nCmdExecOpt, pvarargIn,
pvarargOut);
}
signature for this method in MyDocObjectServer.cpp to the following:
STDMETHODIMP CMyDocObjectServer::XMyOleCommandTarget::QueryStatus(
const GUID* pguidCmdGroup, ULONG cCmds, OLECMD rgCmds[],
OLECMDTEXT* pcmdtext)
{
...
}
This changes the nested class name from XOleCommandTarget to
XMyOleCommandTarget.
METHOD_PROLOGUE_EX(CMyDocObjectServer, OleCommandTarget)
to this:
METHOD_PROLOGUE_EX(CMyDocObjectServer, MyOleCommandTarget)
COleCmdUI state(rgCmds, cCmds, pguidCmdGroup);
to this
CMyOleCmdUI state(rgCmds, cCmds, pguidCmdGroup);
CMyOleCmdUI is the COleCmdUI-derived class that you will create in step
10.
class:
#include "MyDocObjectServer.h"
CDocument-derived class to the following:
return new CMyDocObjectServer(this, pDocSite);
publicly from COleCmdUI. Override the virtual function DoUpdate().
class CMyOleCmdUI : public COleCmdUI
{
public:
CMyOleCmdUI(OLECMD* rgCmds, ULONG cCmds, const GUID* pGroup)
: COleCmdUI(rgCmds, cCmds, pGroup)
{
}
virtual BOOL DoUpdate(CCmdTarget* pTarget, BOOL
bDisableIfNoHandler);
};
#include "MyOleCmdUI.h"
Mfc\Src\Oledoctg.cpp (line# 64 in Visual C++ 5.0.) Change this code in
your CMyOleCmdUI::DoUpdate:
if (bDisableIfNoHandler && !m_bEnableChanged)
{
AFX_CMDHANDLERINFO info;
info.pTarget = NULL;
bResult = pTarget->OnCmdMsg(m_nID, CN_COMMAND, this, &info);
Enable(bResult);
if (bResult || m_bEnableChanged)
m_rgCmds[m_nIndex].cmdf |= OLECMDF_SUPPORTED;
else
m_rgCmds[m_nIndex].cmdf &= ~OLECMDF_SUPPORTED;
}
to this:
if (bDisableIfNoHandler && !m_bEnableChanged)
{
AFX_CMDHANDLERINFO info;
info.pTarget = NULL;
bResult = pTarget->OnCmdMsg(m_nID, CN_COMMAND, this, &info);
if (bResult || m_bEnableChanged)
m_rgCmds[m_nIndex].cmdf |= OLECMDF_SUPPORTED;
else
m_rgCmds[m_nIndex].cmdf &= ~OLECMDF_SUPPORTED;
Enable(bResult);
}
This changes the order in which Enable is called.
file:
#include "afxconv.h"
and add this include statement to the CMyOleCmdUI implementation file:
#include <afxpriv.h>
A default MFC Active Document server that has these fixes applied is available for download from the Microsoft Software Library:
~ AxDocFix.exe (size: 50500 bytes)
ARTICLE-ID: Q119591
TITLE : How to Obtain Microsoft Support Files from Online Services
Keywords : AXSDKDocObjects
Version : WINDOWS:4.0; WINNT:4.2,4.2b,5.0
Platform : WINDOWS winnt
Issue type : kbbugLast Reviewed: August 1, 1998