XmlDocument.IsReadOnly Property

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

public class Sample
{
  public static void Main()
  {
    //Create the XmlDocument.
    XmlDocument doc = new XmlDocument();
    doc.LoadXml("<!DOCTYPE book [<!ENTITY h 'hardcover'>]>" +
                "<book genre='novel' ISBN='1-861001-57-5'>" +
                "<title>Pride And Prejudice</title>" +
                "<style>&h;</style>" +
                "</book>");

    //Determine whether the node is read-only. 
    if (doc.DocumentElement.LastChild.FirstChild.IsReadOnly)
       Console.WriteLine("Entity reference nodes are always read-only");

  }
}

#using <mscorlib.dll>
#using <System.Xml.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml;

int main()
{
    //Create the XmlDocument.
    XmlDocument* doc = new XmlDocument();
    doc->LoadXml(S"<!DOCTYPE book [<!ENTITY h 'hardcover'>]>" 
                 S"<book genre='novel' ISBN='1-861001-57-5'>" 
                 S"<title>Pride And Prejudice</title>" 
                 S"<style>&h;</style>" 
                 S"</book>");

    //Check if the node is read-only.
    if (doc->DocumentElement->LastChild->FirstChild->IsReadOnly)
       Console::WriteLine(S"Entity reference nodes are always read-only");

}