使用带有tinyxpath和tinyxml的xpath获取属性

我正在尝试编写一个函数,它将使用带有tinyxpath库的xpath在文档中为我获取一组XML节点的属性,但我似乎找不到它。我发现TinyxPath上的文档也不是很有启发性。有人能帮我吗?

std::string XMLDocument::GetXPathAttribute(const std::string& attribute)
{
    TiXmlElement* Root = document.RootElement();
    std::string attributevalue;
    if (Root)
    {
        int pos = attribute.find('@');  //make sure the xpath string is for an attribute search
        if (pos != 0xffffffff)
        {
            TinyXPath::xpath_processor proc(Root,attribute.c_str()); 
            TinyXPath::expression_result xresult = proc.er_compute_xpath();

            TinyXPath::node_set* ns = xresult.nsp_get_node_set(); // Get node set from XPath expression, however, I think it might only get me the attribute??

            _ASSERTE(ns != NULL);
            TiXmlAttribute* attrib = (TiXmlAttribute*)ns->XAp_get_attribute_in_set(0);  // This always fails because my node set never contains anything...
            return attributevalue;  // need my attribute value to be in string format

        }

    }
}

用途:

XMLDocument doc;
std::string attrib;
attrib = doc.GetXPathAttribute("@Myattribute");

示例XML:

<?xml version="1.0" ?>
<Test />
<Element>Tony</Element>
<Element2 Myattribute="12">Tb</Element2>