本文整理匯總了VB.NET中System.Xml.XPath.XPathNavigator.Evaluate方法的典型用法代碼示例。如果您正苦於以下問題：VB.NET XPathNavigator.Evaluate方法的具體用法？VB.NET XPathNavigator.Evaluate怎麽用？VB.NET XPathNavigator.Evaluate使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。
在下文中一共展示了XPathNavigator.Evaluate方法的4個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的VB.NET代碼示例。
示例1: XPathDocument
Dim document As XPathDocument = New XPathDocument("books.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()
Dim total As Double = CType(navigator.Evaluate("sum(descendant::book/price)"), Double)
Console.WriteLine("Total price for all books: {0}", total.ToString())示例2: XPathDocument
Dim document As XPathDocument = New XPathDocument("books.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()
Dim query As XPathExpression = navigator.Compile("sum(descendant::book/price)")
Dim total As Double = CType(navigator.Evaluate(query), Double)
Console.WriteLine("Total price for all books: {0}", total.ToString())示例3: XPathDocument
Dim document As XPathDocument = New XPathDocument("contosoBooks.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()
Dim manager As XmlNamespaceManager = New XmlNamespaceManager(navigator.NameTable)
manager.AddNamespace("bk", "http://www.contoso.com/books")
Dim total As Double = CType(navigator.Evaluate("sum(descendant::bk:book/bk:price)", manager), Double)
Console.WriteLine("Total price for all books: {0}", total.ToString())示例4: XPathDocument
Dim document As XPathDocument = New XPathDocument("books.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()
Dim nodes As XPathNodeIterator = navigator.Select("//book")
Dim query As XPathExpression = nodes.Current.Compile("sum(descendant::price)")
Dim total As Double = CType(navigator.Evaluate(query, nodes), Double)
Console.WriteLine("Total price for all books: {0}", total.ToString())