将xml绑定到gridview，及xml节点查询的selectNodes怎么实现多条件查询

XmlDocument   xmldoc   =   new   XmlDocument();
string   xmlstr   =   "<data   name="BackBtnResource1.Text"   xml:space="preserve">
<value>返回</value>
<comment>其它</comment>
</data>"
xmldoc.LoadXml(xmlstr);
XmlNodeList   list   =   xmldoc.SelectNodes("data");
ArrayList   datalist   =   new   ArrayList();
foreach(Xmlnode   node   in   list)
{
Model   m   =   new   Model();
m.attr   =   node.Attributes["name"].value;
xmlnode   subnode   =   node.SelectSingleNode("value");
m.val   =   subnode.innnertext;
subnode   =   node.SelectSingleNode("comment");
m.com   =   subnode.innnertext;
datalist.add(m);
}
gridview.datasource   =   datalist;
gridview.databind();

XmlNodeList list = InvoiceXml.SelectNodes("LineItems/LineItem[ShippingAddressID='" + ShippingAddressID + "' and ShippingMethod='" + ShippingMethod + "' and ReqShipDate='" + ReqShipDate + "']")