C# - Add XML Namespace (xmlns) tag to document

Question

I'm creating an XML document using System.XML in C#.

I'm almost done, but I need to add some similar to the following to the top of my document:

<ABC xmlns="http://www.acme.com/ABC" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" fileName="acmeth.xml" date="2011-09-16T10:43:54.91+01:00" origin="TEST" ref="XX_88888">

I need to add this just below where I have:

<?xml version="1.0" encoding="UTF-8"?>

I create this using the following code:

XmlWriterSettings settings = new XmlWriterSettings { Encoding = Encoding.UTF8, Indent = true };

After this I go on to create my XML document, which is finished now but I need to add this in-between.

Thanks

John

Answer 1

You can add namespace declarations to the root element of an XmlDocument like this:

document.DocumentElement.SetAttribute("xmlns", "http://default-namespace");
document.DocumentElement.SetAttribute("xmlns:ns2", "http://other-namespace");

Answer 2

I think this is what you're after:

using System;
using System.Xml.Linq;

class Test
{
    static void Main()
    {
        XNamespace ns = "http://www.acme.com/ABC";
        DateTimeOffset date = new DateTimeOffset(2011, 9, 16, 10, 43, 54, 91,
                                                 TimeSpan.FromHours(1));
        XDocument doc = new XDocument(
            new XElement(ns + "ABC",
                         new XAttribute("xmlns", ns.NamespaceName),
                         new XAttribute(XNamespace.Xmlns + "xsi",
                              "http://www.w3.org/2001/XMLSchema-instance"),
                         new XAttribute("fileName", "acmeth.xml"),
                         new XAttribute("date", date),
                         new XAttribute("origin", "TEST"),
                         new XAttribute("ref", "XX_88888")));

        Console.WriteLine(doc); 
    }
}