XmlDocument.CreateDocumentType Method

The returned node will have parsed Entities and Notations collections.

Although this method creates the new object in the context of the document, it does not automatically add the new object to the document tree. To add the new object, you must explicitly call one of the node insert methods.

According to the W3C Extensible Markup Language (XML) 1.0 recommendation (www.w3.org/TR/1998/REC-xml-19980210), DocumentType nodes are only allowed within Document nodes. Each XmlDocument can have only one DocumentType node. The DocumentType node must also be inserted before the root element of the XmlDocument (if the document already has a root element, you cannot add a DocumentType node).

If the passed parameters do not combine to build a valid XmlDocumentType, an exception is thrown.

This method has an inheritance demand. Full trust is required to override the CreateDocumentType method. See Inheritance Demands for more information.

This method is a Microsoft extension to the Document Object Model (DOM).

The following example creates a DocumentType node and adds it to an XML document.

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

public class Sample
{
  public static void Main()
  {
    //Create the XmlDocument.
    XmlDocument doc = new XmlDocument();

    //Create a document type node and   
    //add it to the document.
    XmlDocumentType doctype;
    doctype = doc.CreateDocumentType("book", null, null, "<!ELEMENT book ANY>");
    doc.AppendChild(doctype);

    //Create the root element and  
    //add it to the document.
    doc.AppendChild(doc.CreateElement("book"));

    Console.WriteLine("Display the modified XML...");
    doc.Save(Console.Out);
  }
}

.NET Framework

.NET Framework Client Profile

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference