用xpath匹配第一组元素

Question

我有一个看起来像这样的xml文档。

<foo> 
    <bar type="artist"/> Bob Marley </bar> 
    <bar type="artist"/> Peter Tosh </bar> 
    <bar type="artist"/> Marlon Wayans </bar> 
</foo> 
<foo> 
    <bar type="artist"/> Bob Marley </bar> 
    <bar type="artist"/> Peter Tosh </bar> 
    <bar type="artist"/> Marlon Wayans </bar> 
</foo> 
<foo> 
    <bar type="artist"/> Bob Marley </bar> 
    <bar type="artist"/> Peter Tosh </bar> 
    <bar type="artist"/> Marlon Wayans </bar> 
</foo> 

我想构建一个只返回第一组的XPath：

<bar type="artist"/> Bob Marley </a> 
<bar type="artist"/> Peter Tosh </a> 
<bar type="artist"/> Marlon Wayans </a> 

一个怎么会去吗？我尝试过//bar[@type='artist']，但很明显，还有更多。提前致谢。

Answer 1

为了得到一些“索引”节点的唯一子元素：

//foo[1]/bar[@type='artist'] 

〔实施例在C＃：

string xml = 
    @"<root> 
     <foo> 
      <bar type='artist'> Artist 1 </bar> 
      <bar type='artist'> Artist 2 </bar> 
      <bar type='artist'> Artist 3 </bar> 
     </foo> 
     <foo> 
      <bar type='artist'> Artist 1 </bar> 
      <bar type='artist'> Artist 2 </bar> 
      <bar type='artist'> Artist 3 </bar> 
      <bar type='artist'> Artist 4 </bar> 
     </foo> 
    </root>"; 
XmlDocument document = new XmlDocument(); 
document.LoadXml(xml); 

Assert.That(document.SelectNodes(@"/root/foo[1]/bar[@type='artist']").Count, 
           Is.EqualTo(3)); 
Assert.That(document.SelectNodes(@"//foo[1]/bar[@type='artist']").Count, 
           Is.EqualTo(3));