获得Frame或Iframe中的IHTMLDocumnet2接口

IHTMLDocument2* GetDocFromFrame(IHTMLDocument2* pDoc2) { CComPtr<IHTMLDocument3> pDoc3; CComPtr<IHTMLDocument2> pDoc2Frame; hr = pDoc2->QueryInterface(IID_IHTMLDocument3,(void**)&pDoc3) ; if(hr==S_OK) { CComBSTR bstrName("FRAME");//CComBSTR bstrName("Iframe"); CComPtr<IHTMLElementCollection> pElemCollFrame; hr=pDoc3->getElementsByTagName(bstrName,&pElemCollFrame); if (hr!=S_OK) return NULL; long pLength; hr=pElemCollFrame->get_length(&pLength); if(hr!=S_OK) return NULL; for(int i=0;i<pLength;i++) { IDispatch *pDispFrame=NULL; CComVariant vIndex=i; hr=pElemCollFrame->item(vIndex,vIndex,&pDispFrame); if(hr!=S_OK) continue; CComPtr<IHTMLElement> pElemFrame; hr=pDispFrame->QueryInterface(IID_IHTMLElement,(void**)&pElemFrame); if(hr!=S_OK) continue; CComPtr<IHTMLFrameBase2> pFrameBase2; hr=pElemFrame->QueryInterface(IID_IHTMLFrameBase2,(void**)&pFrameBase2); if(hr!=S_OK) continue; CComPtr<IHTMLWindow2> pWindow2; hr=pFrameBase2->get_contentWindow(&pWindow2); if(hr==S_OK) { hr=pWindow2->get_document(&pDoc2Frame); if (hr==S_OK) { return pDoc2Frame; } } } pDispFrame->Release(); } return NULL; }