ActiveX控件访问所在网页的DHTML文档对象模型(MFC）

void CICWXPlayerCtrl::SetHolderID(CICWXPlayerWindowHolder::enumHolderIndex iHolderIndex,LPCTSTR lpszElementID)
{
 IOleClientSite* pClientSite=GetClientSite(); 
 do{
  if(pClientSite==NULL)break;
  CComQIPtr pISP(pClientSite);
  if(pISP==NULL)break;
  CComPtr pIWebBrowser2;
  pISP->QueryService(IID_IWebBrowserApp, IID_IWebBrowser2,
    (void **)&pIWebBrowser2);
  if(pIWebBrowser2==NULL)break;
  CComPtr    spDocument;
  pIWebBrowser2->get_Document(&spDocument);
  CComQIPtr pIHTMLDocument2(spDocument);
  if(pIHTMLDocument2==NULL)break;
  CComPtr pHTMLElementCollection;
  pIHTMLDocument2->get_all(&pHTMLElementCollection);
  if(pHTMLElementCollection==NULL)break;
  COleVariant varName(lpszElementID,VT_BSTR);
  COleVariant varindex;

  CComPtr    spElement;
  pHTMLElementCollection->item(varName,varindex,&spElement);
  if(spElement==NULL)break;
  //is it an Iframe?
  CComQIPtr pFrame(spElement);
  if(pFrame){
   switch(iHolderIndex){
   case CICWXPlayerWindowHolder::WebHolder:
   case CICWXPlayerWindowHolder::TextHolder:
    m_holders[iHolderIndex].SetTarget(spElement);
    break;
   }
  }
  CComQIPtr pObjectElement(spElement);
  if(pObjectElement==NULL)break;
  CComPtr    spObject;
  pObjectElement->get_object(&spObject);  
  m_holders[iHolderIndex].SetTarget(spObject);
 }
 while(FALSE);
}