Articolo
11/17/2011

XmlNamespaceManager.AddNamespace Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Adds the given namespace to the collection.

Namespace: System.Xml
Assembly: System.Xml (in System.Xml.dll)

Syntax

'Declaration
Public Overridable Sub AddNamespace ( _
    prefix As String, _
    uri As String _
)

public virtual void AddNamespace(
    string prefix,
    string uri
)

Parameters

prefix
Type: System.String
The prefix to associate with the namespace being added. Use String.Empty to add a default namespace.

uri
Type: System.String
The namespace to add.

Exceptions

Exception	Condition
ArgumentException	The value for prefix is "xml" or "xmlns".
ArgumentNullException	The value for prefix or uri is nulla null reference (Nothing in Visual Basic).

Remarks

XmlNamespaceManager does not check prefix and uri for conformance.

XmlReader checks names, including prefixes and namespaces, to ensure they are valid XML names according to the World Wide Web Consortium (W3C) specification. XmlNamespaceManager is used internally by XmlReader, so to avoid a duplication of efforts, XmlNamespaceManager assumes all prefixes and namespaces are valid.

If the prefix and namespace already exist within the current scope, the new prefix and namespace pair will replace the existing prefix/namespace combination. The same prefix and namespace combination can exist across different scopes.

The following prefix/namespace pairs are added by default to the XmlNamespaceManager. They can be determined at any scope.

Prefix	Namespace
xmlns	http://www.w3.org/2000/xmlns/ (the xmlns prefix namespace)
xml	http://www.w3.org/XML/1998/namespace (the XML namespace)
String.Empty	String.Empty (the empty namespace). This value can be reassigned a different prefix. For example, defines the default namespace to be the empty namespace

Examples

Dim output As New StringBuilder()

Dim xmlFrag As String = _
      "<root>" & _
        "<data>" & _
         "<items>" & _
          "<item id='1'>" & _
          "</item>" & _
         "</items>" & _
        "</data>" & _
        "</root>"

Using reader As XmlReader = XmlReader.Create(New StringReader(xmlFrag))
    Dim nsmanager As New XmlNamespaceManager(reader.NameTable)
    nsmanager.AddNamespace("msbooks", "www.microsoft.com/books")
    nsmanager.PushScope()
    nsmanager.AddNamespace("msstore", "www.microsoft.com/store")

    Dim prefix As String
    For Each prefix In nsmanager
        output.AppendLine(("Prefix" + prefix + _
                           " Namespace=" + nsmanager.LookupNamespace(prefix)))
    Next prefix
End Using
OutputTextBlock.Text = output.ToString()


                StringBuilder output = new StringBuilder();

                // Create the string containing the XML to read.
                String xmlFrag =
                    @"<root>
                        <data>
                            <items>
                                <item id='1'>
                                </item>
                            </items>
                        </data>
                        </root>";

                using (XmlReader reader = XmlReader.Create(new StringReader(xmlFrag)))
                {
                    XmlNamespaceManager nsmanager = new XmlNamespaceManager(reader.NameTable);
                    nsmanager.AddNamespace("msbooks", "www.microsoft.com/books");
                    nsmanager.PushScope();
                    nsmanager.AddNamespace("msstore", "www.microsoft.com/store");

                    foreach (String prefix in nsmanager)
                    {
                        output.AppendLine("Prefix" + prefix + " Namespace=" +
                            nsmanager.LookupNamespace(prefix));
                    }
                }
                OutputTextBlock.Text = output.ToString();

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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