LINQ TO XML如何查找某一节点

[baidu_27371507]

各位好！
我有一XML文档，如何定位到指定人员啊？
我用下面语句得出的是空的啊。
IEnumerable<XElement> query =
from ele in xe.Elements("DataProperty ")
where (ele.Attribute("propertyname").Value == "loginName" &&
ele.Element("DataProperty").Value == "lisi")
select ele;

String xml = null;
foreach (XElement ele in query)
{
xml = xml + e.ToString() + "\n ------- \n";
}
MessageBox.Show(xml);



<?xml version="1.0" encoding="UTF-8"?>
<DataPojo type="IEOrganizationInfo" version="1" isnull="false" valuecount="1">
<DataProperty propertyname="personArray" valuetype="10" isnull="false" length="1662">
<DataPojo type="PersonInfoParam_All" version="1" valuecount="20" isnull="false">
<DataProperty propertyname="otypeName" valuetype="1" isnull="true"/>
<DataProperty propertyname="birthday" valuetype="1" isnull="true"/>
<DataProperty propertyname="per_sort" valuetype="1" isnull="false">2</DataProperty>
<DataProperty propertyname="sex" valuetype="1" isnull="true"/>
<DataProperty propertyname="ocupationName" valuetype="1" isnull="true"/>
<DataProperty propertyname="accountId" valuetype="3" value="670869647114347"/>
<DataProperty propertyname="secondOcupationName" valuetype="7" value="" isnull="false" length="0"/>
<DataProperty propertyname="trueName" valuetype="1" isnull="false">张三</DataProperty>
<DataProperty propertyname="discursion" valuetype="1" isnull="true"/>
<DataProperty propertyname="familyPhone" valuetype="1" isnull="true"/>
<DataProperty propertyname="officePhone" valuetype="1" isnull="true"/>
<DataProperty propertyname="departmentName" valuetype="7" value="" isnull="true" length="0"/>
<DataProperty propertyname="passWord" valuetype="1" isnull="false">123456</DataProperty>
<DataProperty propertyname="staffNumber" valuetype="1" isnull="false">601404070621</DataProperty>
<DataProperty propertyname="familyAddress" valuetype="1" isnull="true"/>
<DataProperty propertyname="id" valuetype="3" value="-1570456924338502774"/>
<DataProperty propertyname="identity" valuetype="1" isnull="true"/>
<DataProperty propertyname="mobilePhone" valuetype="1" isnull="false"/>
<DataProperty propertyname="email" valuetype="1" isnull="false">***@sina.com</DataProperty>
<DataProperty propertyname="loginName" valuetype="1" isnull="false">zhangsan</DataProperty>
</DataPojo>
<DataPojo type="PersonInfoParam_All" version="1" valuecount="20" isnull="false">
<DataProperty propertyname="otypeName" valuetype="1" isnull="true"/>
<DataProperty propertyname="birthday" valuetype="1" isnull="true"/>
<DataProperty propertyname="per_sort" valuetype="1" isnull="false">3</DataProperty>
<DataProperty propertyname="sex" valuetype="1" isnull="true"/>
<DataProperty propertyname="ocupationName" valuetype="1" isnull="true"/>
<DataProperty propertyname="accountId" valuetype="3" value="670869647114347"/>
<DataProperty propertyname="secondOcupationName" valuetype="7" value="" isnull="false" length="0"/>
<DataProperty propertyname="trueName" valuetype="1" isnull="false">李斯</DataProperty>
<DataProperty propertyname="discursion" valuetype="1" isnull="true"/>
<DataProperty propertyname="familyPhone" valuetype="1" isnull="true"/>
<DataProperty propertyname="officePhone" valuetype="1" isnull="true"/>
<DataProperty propertyname="departmentName" valuetype="7" value="" isnull="true" length="0"/>
<DataProperty propertyname="passWord" valuetype="1" isnull="false">123456</DataProperty>
<DataProperty propertyname="staffNumber" valuetype="1" isnull="false">601404070620</DataProperty>
<DataProperty propertyname="familyAddress" valuetype="1" isnull="true"/>
<DataProperty propertyname="id" valuetype="3" value="1306499082168780299"/>
<DataProperty propertyname="identity" valuetype="1" isnull="true"/>
<DataProperty propertyname="mobilePhone" valuetype="1" isnull="false"/>
<DataProperty propertyname="email" valuetype="1" isnull="false">[e-mail]</DataProperty>
<DataProperty propertyname="loginName" valuetype="1" isnull="false">lisi</DataProperty>
</DataPojo>
</DataProperty>


</DataPojo>

[baidu_27371507]

我就是想修改某个人员departmentName（部门名称）的内容。

[娃都会打酱油了]

你这个xml烂透了……

[xxxxxue]

xml 太 烂 了 叭 !!!!!