XPathNavigator.NamespaceURI 属性

当在派生类中被重写时，获取当前节点的命名空间 URI。

**命名空间:**System.Xml.XPath
**程序集:**System.Xml（在 system.xml.dll 中）

语法

声明
Public MustOverride ReadOnly Property NamespaceURI As String
用法
Dim instance As XPathNavigator
Dim value As String

value = instance.NamespaceURI

public abstract string NamespaceURI { get; }

public:
virtual property String^ NamespaceURI {
    String^ get () abstract;
}

/** @property */
public abstract String get_NamespaceURI ()

public abstract function get NamespaceURI () : String

属性值

一个 String，包含当前节点的命名空间 URI；否则，如果当前节点没有命名空间 URI，则为 String.Empty。

备注

返回的命名空间 URI 取决于当前节点的 XPathNodeType。

NamespaceURI 属性为节点 <bk:book xmlns:bk='urn:samples'> 返回 urn:samples。

只有 Element 节点和 AttributeXPathNodeType 节点才可具有命名空间 URI。

示例

下面的示例以递归方式循环访问节点树，并显示有关 Element 和 Text 节点的信息。

Shared Sub XPathNavigatorMethods_MoveToNext()

    Dim document As XPathDocument = New XPathDocument("books.xml")
    Dim navigator As XPathNavigator = document.CreateNavigator()
    Dim nodeset As XPathNodeIterator = navigator.Select("descendant::book[author/last-name='Melville']")

    While nodeset.MoveNext()
        ' Clone iterator here when working with it.
        RecursiveWalk(nodeset.Current.Clone())
    End While

End Sub

Shared Sub RecursiveWalk(ByVal navigator As XPathNavigator)

    Select Case navigator.NodeType
        Case XPathNodeType.Element
            If navigator.Prefix = String.Empty Then
                Console.WriteLine("<{0}>", navigator.LocalName)
            Else
                Console.Write("<{0}:{1}>", navigator.Prefix, navigator.LocalName)
                Console.WriteLine(vbTab + navigator.NamespaceURI)
            End If
        Case XPathNodeType.Text
            Console.WriteLine(vbTab + navigator.Value)
    End Select

    If navigator.MoveToFirstChild() Then
        Do
            RecursiveWalk(navigator)
        Loop While (navigator.MoveToNext())

        navigator.MoveToParent()
        If (navigator.NodeType = XPathNodeType.Element) Then
            Console.WriteLine("</{0}>", navigator.Name)
        End If
    Else
        If navigator.NodeType = XPathNodeType.Element Then
            Console.WriteLine("</{0}>", navigator.Name)
        End If
    End If

End Sub

static void XPathNavigatorMethods_MoveToNext()
{
    
    XPathDocument document = new XPathDocument("books.xml");
    XPathNavigator navigator = document.CreateNavigator();
    XPathNodeIterator nodeset = navigator.Select("descendant::book[author/last-name='Melville']");

    while (nodeset.MoveNext())
    {
        // Clone iterator here when working with it.
        RecursiveWalk(nodeset.Current.Clone());
    }
}

public static void RecursiveWalk(XPathNavigator navigator)
{
    switch (navigator.NodeType)
    {
        case XPathNodeType.Element:
            if (navigator.Prefix == String.Empty)
                Console.WriteLine("<{0}>", navigator.LocalName);
            else
                Console.Write("<{0}:{1}>", navigator.Prefix, navigator.LocalName);
                Console.WriteLine("\t" + navigator.NamespaceURI);
            break;
        case XPathNodeType.Text:
            Console.WriteLine("\t" + navigator.Value);
            break;
    }

    if (navigator.MoveToFirstChild())
    {
        do
        {
            RecursiveWalk(navigator);
        } while (navigator.MoveToNext());

        navigator.MoveToParent();
        if (navigator.NodeType == XPathNodeType.Element)
            Console.WriteLine("</{0}>", navigator.Name);
    }
    else
    {
        if (navigator.NodeType == XPathNodeType.Element)
        {
            Console.WriteLine("</{0}>", navigator.Name);
       }
    }
}

该示例采用 books.xml 文件作为输入。

<bookstore>
    <book genre="autobiography" publicationdate="1981-03-22" ISBN="1-861003-11-0">
        <title>The Autobiography of Benjamin Franklin</title>
        <author>
            <first-name>Benjamin</first-name>
            <last-name>Franklin</last-name>
        </author>
        <price>8.99</price>
    </book>
    <book genre="novel" publicationdate="1967-11-17" ISBN="0-201-63361-2">
        <title>The Confidence Man</title>
        <author>
            <first-name>Herman</first-name>
            <last-name>Melville</last-name>
        </author>
        <price>11.99</price>
    </book>
    <book genre="philosophy" publicationdate="1991-02-15" ISBN="1-861001-57-6">
        <title>The Gorgias</title>
        <author>
            <name>Plato</name>
        </author>
        <price>9.99</price>
    </book>
</bookstore>

平台

Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

XPathNavigator 类
XPathNavigator 成员
System.Xml.XPath 命名空间
XPathNodeType
Prefix