XmlSerializerNamespaces Class

The XmlSerializerNamespaces contains a collection of XML namespaces, each with an associated prefix. The XmlSerializer uses an instance of the XmlSerializerNamespaces class to create qualified names in an XML document.

XML namespaces contained by the XmlSerializerNamespaces must conform to the www.w3.org specification named Namespaces in XML.

XML namespaces provide a way to qualify the names of XML elements and attributes in XML documents. A qualified name consists of a prefix and a local name, separated by a colon. The prefix functions only as a placeholder; it is mapped to a URI that specifies a namespace. The combination of the universally-managed URI namespace and the local name produces a name that is guaranteed to be universally unique.

To create qualified names in an XML document:

1. Create an XmlSerializerNamespaces instance.

2. Add each prefix and namespace pair that you want to the instance.

3. Apply the appropriate.NET attribute to each property or class that the XmlSerializer serializes into an XML document. The available attributes are:

• XmlArrayAttribute

• XmlArrayItemAttribute

• XmlAttributeAttribute

• XmlElementAttribute

• XmlRootAttribute

• XmlTypeAttribute

1. Set the Namespace property of each attribute to one of the namespace values from the XmlSerializerNamespaces object.

2. Pass the XmlSerializerNamespaces to the Serialize method of the XmlSerializer.

Note
The creation of an empty namespace and prefix pair is not supported. That is, you cannot create a pair using the following code:

XmlSerializerNamespaces ns = new XmlSerializerNamespaces(); 
ns.Add("", "");

The following example creates an XmlSerializerNamespaces object, and adds two prefix and namespace pairs to it. The example then passes the XmlSerializerNamespaces to the Serialize method, which serializes a Books object into an XML document. Using the XmlSerializerNamespaces object, the Serialize method qualifies each XML element and attribute with one of the two namespaces.

using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;

public class Run
{
   public static void Main()
   {
      Run test = new Run();
      test.SerializeObject("XmlNamespaces.xml");
   }

   public void SerializeObject(string filename)
   {
      XmlSerializer s = new XmlSerializer(typeof(Books));
      // Writing a file requires a TextWriter.
      TextWriter t = new StreamWriter(filename);

      /* Create an XmlSerializerNamespaces object and add two
      prefix-namespace pairs. */
      XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
      ns.Add("books", "http://www.cpandl.com");
      ns.Add("money", "http://www.cohowinery.com");

      // Create a Book instance.
      Book b = new Book();
      b.TITLE = "A Book Title";
      Price p = new Price();
      p.price = (decimal) 9.95;
      p.currency = "US Dollar";
      b.PRICE = p;
      Books bks = new Books();
      bks.Book = b;
      s.Serialize(t,bks,ns);
      t.Close();
   }
}

public class Books
{
   [XmlElement(Namespace = "http://www.cohowinery.com")]
   public Book Book;
}

[XmlType(Namespace ="http://www.cpandl.com")]
public class Book
{
   [XmlElement(Namespace = "http://www.cpandl.com")]
   public string TITLE;
   [XmlElement(Namespace ="http://www.cohowinery.com")]
   public Price PRICE;
}

public class Price
{
   [XmlAttribute(Namespace = "http://www.cpandl.com")]
   public string currency;
   [XmlElement(Namespace = "http://www.cohowinery.com")]
   public decimal price;
}

.NET Framework

.NET Framework Client Profile

Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Other Resources