如何使用TinyXml解析特定元素

我想解析一组元素TinyXml输出。本质上，我需要挑选出任何端口元素"portid"端口属性的状态为"open"（如下所示为端口 23）。

最好的方法是什么？以下是 TinyXml 输出的（简化）列表：

<?xml version="1.0" ?>
<nmaprun>
    <host>
        <ports>
            <port protocol="tcp" portid="22">
                <state state="filtered"/>
            </port>
            <port protocol="tcp" portid="23">
                <state state="open "/>
            </port>
            <port protocol="tcp" portid="24">
                <state state="filtered" />
            </port>
            <port protocol="tcp" portid="25">
                <state state="filtered" />
            </port>
            <port protocol="tcp" portid="80">
                <state state="filtered" />
            </port>
        </ports>
    </host>
</nmaprun>

这将大致做到这一点：

    TiXmlHandle docHandle( &doc );

    TiXmlElement* child = docHandle.FirstChild( "nmaprun" ).FirstChild( "host" ).FirstChild( "ports" ).FirstChild( "port" ).ToElement();

    int port;
    string state;
    for( child; child; child=child->NextSiblingElement() )
    {

        port = atoi(child->Attribute( "portid"));

        TiXmlElement* state_el = child->FirstChild()->ToElement();

        state = state_el->Attribute( "state" );

        if ("filtered" == state)
            cout << "port: " << port << " is filtered! " << endl;
        else
            cout << "port: " << port << " is unfiltered! " << endl;
    }