Mega Code Archive
Use the XPath return type to determine how to process the XPath expression
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using System;
using System.Xml;
using System.Xml.XPath;
public class XPathExpressionExample
{
public static void Main()
{
XPathDocument document = new XPathDocument("contosoBooks.xml");
XPathNavigator navigator = document.CreateNavigator();
XPathExpression expression1 = XPathExpression.Compile(".//bk:price/text()*10"); // Returns a number.
XPathExpression expression2 = XPathExpression.Compile("bk:bookstore/bk:book/bk:price"); // Returns a nodeset.
XmlNamespaceManager manager = new XmlNamespaceManager(navigator.NameTable);
manager.AddNamespace("bk", "http://www.yourname.com/books");
expression1.SetContext(manager);
expression2.SetContext(manager);
Evaluate(expression1, navigator);
Evaluate(expression2, navigator);
}
public static void Evaluate(XPathExpression expression, XPathNavigator navigator)
{
switch (expression.ReturnType)
{
case XPathResultType.Number:
Console.WriteLine(navigator.Evaluate(expression));
break;
case XPathResultType.NodeSet:
XPathNodeIterator nodes = navigator.Select(expression);
while (nodes.MoveNext())
{
Console.WriteLine(nodes.Current.ToString());
}
break;
case XPathResultType.Boolean:
if ((bool)navigator.Evaluate(expression))
Console.WriteLine("True!");
break;
case XPathResultType.String:
Console.WriteLine(navigator.Evaluate(expression));
break;
}
}
}
/*
<bookstore xmlns="http://www.yourname.com/books">
<book genre="autobiography" publicationdate="1999-12-12" ISBN="1-111111-11-1">
<title>A</title>
<author>
<first-name>X</first-name>
<last-name>Y</last-name>
</author>
<price>8.99</price>
</book>
<book genre="novel" publicationdate="2000-01-01" ISBN="0-201-63361-2">
<title>Java</title>
<author>
<first-name>Q</first-name>
<last-name>Q</last-name>
</author>
<price>11.99</price>
</book>
<book genre="philosophy" publicationdate="1991-02-15" ISBN="1-22222-57-6">
<title>C#</title>
<author>
<name>Author</name>
</author>
<price>9.99</price>
</book>
</bookstore>
*/
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