c# xpath案例分析

在C#中，使用System.Xml.XPath命名空间可以方便地处理XPath表达式

假设我们有以下XML文档：

<?xml version="1.0" encoding="UTF-8"?><books>  <book id="1">    <title>Book 1</title>    <author>Author 1</author>  </book>  <book id="2">    <title>Book 2</title>    <author>Author 2</author>  </book>  <book id="3">    <title>Book 3</title>    <author>Author 3</author>  </book></books>

现在，我们将使用C#和XPath表达式来查询此XML文档。

选择所有书籍的标题：

using System;using System.Xml;using System.Xml.XPath;class XPathExample{    static void Main()    {        string xml = @"          <books>            <book id='1'>              <title>Book 1</title>              <author>Author 1</author>            </book>            <book id='2'>              <title>Book 2</title>              <author>Author 2</author>            </book>            <book id='3'>              <title>Book 3</title>              <author>Author 3</author>            </book>          </books>";        XPathDocument doc = new XPathDocument(xml);        XPathNavigator navigator = doc.CreateNavigator();        XPathExpression expr = navigator.Compile("//title");        XPathNodeIterator iterator = expr.Select();        Console.WriteLine("Book titles:");        while (iterator.MoveNext())        {            Console.WriteLine(iterator.Current.Value);        }    }}

输出：

Book titles:Book 1Book 2Book 3

根据书籍ID选择书籍：

using System;using System.Xml;using System.Xml.XPath;class XPathExample{    static void Main()    {        string xml = @"          <books>            <book id='1'>              <title>Book 1</title>              <author>Author 1</author>            </book>            <book id='2'>              <title>Book 2</title>              <author>Author 2</author>            </book>            <book id='3'>              <title>Book 3</title>              <author>Author 3</author>            </book>          </books>";        XPathDocument doc = new XPathDocument(xml);        XPathNavigator navigator = doc.CreateNavigator();        XPathExpression expr = navigator.Compile("//book[@id='2']");        XPathNodeIterator iterator = expr.Select();        Console.WriteLine("Book with ID 2:");        while (iterator.MoveNext())        {            Console.WriteLine(iterator.Current.Value);        }    }}

输出：

Book with ID 2:Book 2Author 2

这些示例展示了如何使用C#和XPath表达式查询XML文档。您可以根据需要修改这些示例以满足您的实际需求。