VC++读取XML文件生成树

void CMonitorEmulationView::LoadTree(){    HTREEITEM CityTree,CompTree;    char path[256];    memset(path,0,256);    GetModuleFileName(NULL,path,256);        LPCTSTR urf="TreeXML.xml";    strcat(p,urf);    xml::IXMLDOMDocumentPtr pXMLDoc(__uuidof(xml::DOMDocument));  if(!PathFileExists(path))        return;    try    {        pXMLDoc->load(path);    }    catch(_com_error& e)    {        MessageBox("文件读取失败: " + e.Description(), "错误", MB_ICONWARNING);           return;    }         xml::IXMLDOMNodeListPtr pNodeList=NULL;    xml::IXMLDOMElementPtr spElement;    HRESULT hr = pXMLDoc->get_documentElement(&spElement);   //获取根结点    CComBSTR strTagName;    hr = spElement->get_tagName(&strTagName);    xml::IXMLDOMNodeListPtr spNodeList;    hr = spElement->get_childNodes(&spNodeList);   //获取子结点列表    long lCount;                                           hr = spNodeList->get_length(&lCount);    for (long i=0; i<lCount; ++i)    {        CComVariant varNodeValue;        xml::IXMLDOMNodePtr spNode;        xml::DOMNodeType NodeType;        xml::IXMLDOMNodeListPtr spChildNodeList;        hr = spNodeList->get_item(i, &spNode);         //获取结点        hr = spNode->get_nodeType(&NodeType);     //获取结点信息的类型        xml::IXMLDOMNamedNodeMapPtr pAttrs = NULL;         xml::IXMLDOMNodePtr pAttrItem;        spNode->get_attributes(&pAttrs);        long nCount ;        pAttrs->get_length(&nCount);        for(int i = 0 ; i < nCount ; i++)        {                             pAttrs->get_item(i,&pAttrItem);            //我们可以通过函数get_nodeName,get_nodeTypedValue得到属性名和属性值            //也可以直接得到            CString strAttrName   = (char*)(_bstr_t)pAttrItem->nodeName;            CString strAttrValue  = (char*)(_bstr_t)pAttrItem->nodeTypedValue;            CityTree=m_wndTreeCtrl.InsertItem(_bstr_t(strAttrValue),userItem[0]);//父项1插入子项        }        if (NODE_ELEMENT == NodeType)        {            hr = spNode->get_childNodes(&spChildNodeList);            long childLen;            hr = spChildNodeList->get_length(&childLen);            for (int j=0; j<childLen; ++j)            {                xml::IXMLDOMNodePtr spChildNode;                CComBSTR value;                hr = spChildNodeList->get_item(j, &spChildNode);                hr = spChildNode->get_nodeName(&value);            //获取结点名字                hr = spChildNode->get_text(&value);                //获取结点的值                                CString strValue=(char*)(_bstr_t)value;                strValue.TrimRight();                CompTree=m_wndTreeCtrl.InsertItem((_bstr_t)strValue,CityTree);//父项1插入子项                spChildNode.Release();            }        }        spNode.Release();        spChildNodeList.Release();    }    spNodeList.Release();    spElement.Release();    pXMLDoc.Release();}