Persist ActiveX Controls At Runtime

BOOL PersistActiveX(CArchive& ar, CWnd* pActiveX)
{
 ASSERT(pActiveX);

 HRESULT hr = E_FAIL;

 // Create an archive stream
 CArchiveStream stm(&ar);
 LPPERSISTSTREAMINIT pPersStm = NULL;
 LPUNKNOWN lpUnk = pActiveX->GetControlUnknown();

 if(lpUnk)
 {
  // We have the IUnknown interface, so 
  // get the IPersistStreamInit
  lpUnk->QueryInterface(IID_IPersistStreamInit, 
                        (LPVOID*)&pPersStm);

  if(pPersStm)
  {
   // We have the relevant interface so load or save the data
   // based on the type of archive we have.
   if(ar.IsLoading())
   {
    hr = pPersStm->Load(&stm);
   }
   else
   {
    hr = pPersStm->Save(&stm, FALSE);
   }
  }

  // Must release the interface
  pPersStm->Release();
 }

 return SUCCEEDED(hr);
}

PersistActiveX(ar, GetDlgItem(IDC_SOMEACTIVEX));