请问GridView控件如何绑不定无XSD的XML文件

list.xml如下,我想显示list节点的各字段没示出来,试了很多个xpath也没反应
<?xml version="1.0" encoding="utf-8"?>
<site>
  <NewList>
    <list>
      <id>1</id>
      <username>1</username>
      <email>1</email>
      <posttime>2006-4-17 13:19:59</posttime>
      <text>1</text>
    </list>
    <list>
      <id>2</id>
      <username>2</username>
      <email>2</email>
      <posttime>2006-4-17 13:40:38</posttime>
      <text>2</text>
    </list>
    <list>
      <id>3</id>
      <username>3</username>
      <email>3</email>
      <posttime>2006-4-17 13:40:40</posttime>
      <text>3</text>
    </list>
  </NewList>
</site>