XmlNamespaceManager Class

Definition

Namespace:

System.Xml

Assembly:

System.Xml.ReaderWriter.dll

Source:

XmlNamespacemanager.cs

Resolves, adds, and removes namespaces to a collection and provides scope management for these namespaces.

public ref class XmlNamespaceManager : System::Collections::IEnumerable, System::Xml::IXmlNamespaceResolver

public class XmlNamespaceManager : System.Collections.IEnumerable, System.Xml.IXmlNamespaceResolver

type XmlNamespaceManager = class
    interface IEnumerable
    interface IXmlNamespaceResolver

Public Class XmlNamespaceManager
Implements IEnumerable, IXmlNamespaceResolver

Inheritance

Object

XmlNamespaceManager

Derived

System.Windows.Data.XmlNamespaceMappingCollection

System.Xml.Xsl.XsltContext

Implements

IEnumerable IXmlNamespaceResolver

Remarks

For general information about how namespaces are declared and used in XML documents, see Managing Namespaces in an XML Document.

XmlNamespaceManager stores prefixes and namespaces as strings. Here's a summary of management and lookup tasks you can perform with this class. For more information and examples, follow the links to the reference page for each method or property.

To	Use
Add a namespace	AddNamespace method
Remove a namespace	RemoveNamespace method
Find the URI for the default namespace	DefaultNamespace property
Find the URI for a namespace prefix	LookupNamespace method
Find the prefix for a namespace URI	LookupPrefix method
Get a list of namespaces in the current node	GetNamespacesInScope method
Scope a namespace	PushScope and PopScope methods
Check whether a prefix is defined in the current scope	HasNamespace method
Get the name table used to look up prefixes and URIs	NameTable property

To add namespaces to the namespace manager, you create a XmlNamespaceManager object and then use the AddNamespace method. Default prefix and namespace pairs are automatically added to the namespace manager on creation.

When you create the namespace manager, you can specify a name table from the XmlReader, XsltContext, or XmlDocument class, and then use the AddNamespace method to add the namespaces.

You can supply the XmlNamespaceManager object as a parameter to the SelectNodes or SelectSingleNode method of the XmlDocument class to execute XPath query expressions that reference namespace-qualified element and attribute names.

The namespace manager assumes that prefixes and namespaces have already been verified and conform to the W3C Namespaces specification. The namespace manager does not perform any validation.

The namespace manager atomizes the strings when they are added by using the AddNamespace method and when a lookup is performed by using the LookupNamespace or LookupPrefix method.

The namespace manager implements enumeration support in addition to adding and retrieving namespaces. You can loop through the information saved in the namespace manager by using the foreach construct. For example, if you create a namespace manager with the name nsmanager, you can iterate through the table by using foreach (String prefix in nsmanager).

Because the namespace manager provides a string comparison with the prefix and namespaces as objects, there is a performance improvement when using the namespace manager over the direct comparison of a string.

The following code example shows how to bind the prefix xsd with the namespace URI of http://www.w3.org/2001/XMLSchema and add it to the namespace manager:

nsmgr.AddNamespace("xsd", "http://www.w3.org/2001/XMLSchema")  

nsmgr.AddNamespace("xsd", "http://www.w3.org/2001/XMLSchema");  

You can then find the namespace by using the LookupNamespace method:

nsmgr.LookupNamespace("xsd")  

nsmgr.LookupNamespace("xsd");  

The following example creates an XmlNamespaceManager by using the name table from an XML reader:

Dim reader As New XmlTextReader("myfile.xml")  
Dim nsmanager As New XmlNamespaceManager(reader.NameTable)  
nsmanager.AddNamespace("msbooks", "www.microsoft.com/books")  
nsmanager.PushScope()  
nsmanager.AddNamespace("msstore", "www.microsoft.com/store")  
While reader.Read()  
    Console.WriteLine("Reader Prefix:{0}", reader.Prefix)  
    Console.WriteLine("XmlNamespaceManager Prefix:{0}",  
     nsmanager.LookupPrefix(nsmanager.NameTable.Get(reader.NamespaceURI)))  
End While  

XmlTextReader reader = new XmlTextReader("myfile.xml");  
XmlNamespaceManager nsmanager = new XmlNamespaceManager(reader.NameTable);  
nsmanager.AddNamespace("msbooks", "www.microsoft.com/books");  
nsmanager.PushScope();  
nsmanager.AddNamespace("msstore", "www.microsoft.com/store");  
while (reader.Read())  
{  
    Console.WriteLine("Reader Prefix:{0}", reader.Prefix);  
    Console.WriteLine("XmlNamespaceManager Prefix:{0}",  
    nsmanager.LookupPrefix(nsmanager.NameTable.Get(reader.NamespaceURI)));  
}  

Constructors

XmlNamespaceManager(XmlNameTable)

Initializes a new instance of the XmlNamespaceManager class with the specified XmlNameTable.

Properties

DefaultNamespace	Gets the namespace URI for the default namespace.
NameTable	Gets the XmlNameTable associated with this object.

Methods

AddNamespace(String, String)	Adds the given namespace to the collection.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetEnumerator()	Returns an enumerator to use to iterate through the namespaces in the XmlNamespaceManager.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetNamespacesInScope(XmlNamespaceScope)	Gets a collection of namespace names keyed by prefix which can be used to enumerate the namespaces currently in scope.
GetType()	Gets the Type of the current instance. (Inherited from Object)
HasNamespace(String)	Gets a value indicating whether the supplied prefix has a namespace defined for the current pushed scope.
LookupNamespace(String)	Gets the namespace URI for the specified prefix.
LookupPrefix(String)	Finds the prefix declared for the given namespace URI.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
PopScope()	Pops a namespace scope off the stack.
PushScope()	Pushes a namespace scope onto the stack.
RemoveNamespace(String, String)	Removes the given namespace for the given prefix.
ToString()	Returns a string that represents the current object. (Inherited from Object)

Extension Methods

Cast<TResult>(IEnumerable)	Casts the elements of an IEnumerable to the specified type.
OfType<TResult>(IEnumerable)	Filters the elements of an IEnumerable based on a specified type.
AsParallel(IEnumerable)	Enables parallelization of a query.
AsQueryable(IEnumerable)	Converts an IEnumerable to an IQueryable.

See also

• XML Documents and Data
• Managing Namespaces in an XML Document