XPathResultType.Boolean : XPath « XML « VB.Net
XPathResultType.Boolean
Imports System
Imports System.Xml
Imports System.Xml.XPath
Public Class MainClass
Public Shared Sub Main()
Dim document As XPathDocument = New XPathDocument("contosoBooks.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()
Dim expression1 As XPathExpression = XPathExpression.Compile(".//bk:price/text()*10") ' Returns a number.
Dim expression2 As XPathExpression = XPathExpression.Compile("bk:bookstore/bk:book/bk:price") ' Returns a nodeset.
Dim manager As XmlNamespaceManager = New XmlNamespaceManager(navigator.NameTable)
manager.AddNamespace("bk", "http://www.yourname.com/books")
expression1.SetContext(manager)
expression2.SetContext(manager)
Evaluate(expression1, navigator)
Evaluate(expression2, navigator)
End Sub
Public Shared Sub Evaluate(ByVal expression As XPathExpression, ByVal navigator As XPathNavigator)
Select Case expression.ReturnType
Case XPathResultType.Boolean
If CType(navigator.Evaluate(expression), Boolean) Then
Console.WriteLine("True!")
End If
End Select
End Sub
End Class
'<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="1-861001-57-6">
' <title>C#</title>
' <author>
' <name>Author</name>
' </author>
' <price>9.99</price>
' </book>
'</bookstore>
