HRESULT hr;//用于存放函数调用结果
IHTMLDocument2 * pfmDoc2;
IHTMLFramesCollection2 *pCol=NULL;
hr=pDoc2->get_frames(&pCol);
if ( FAILED(hr))return false;
VARIANT vFrame,vIndex;
CString main="mainframe";
vIndex.vt=VT_BSTR;
vIndex.bstrVal = main.AllocSysString();
hr=pCol->item(&vIndex,&vFrame);
if ( FAILED(hr))return false;
IHTMLWindow2 *pWin=(IHTMLWindow2 *)vFrame.pdispVal;
IHTMLDocument2 *pDoc22=NULL;
hr=pWin->get_document(&pDoc22);
IHTMLDocument2 * pfmDoc2;
IHTMLFramesCollection2 *pCol=NULL;
hr=pDoc2->get_frames(&pCol);
if ( FAILED(hr))return false;
VARIANT vFrame,vIndex;
CString main="mainframe";
vIndex.vt=VT_BSTR;
vIndex.bstrVal = main.AllocSysString();
hr=pCol->item(&vIndex,&vFrame);
if ( FAILED(hr))return false;
IHTMLWindow2 *pWin=(IHTMLWindow2 *)vFrame.pdispVal;
IHTMLDocument2 *pDoc22=NULL;
hr=pWin->get_document(&pDoc22);
if ( FAILED(hr))return false;
https://msdn.microsoft.com/en-us/library/aa752400(v=vs.85).aspx