How can I write xml with a namespace and prefix with XElement?

Solution 1:

Here is a small example that creates the output you want:

using System;
using System.Xml.Linq;

class Program
{
    static void Main()
    {
        XNamespace ci = "http://somewhere.com";
        XNamespace ca = "http://somewhereelse.com";

        XElement element = new XElement("root",
            new XAttribute(XNamespace.Xmlns + "ci", ci),
            new XAttribute(XNamespace.Xmlns + "ca", ca),
                new XElement(ci + "field1", "test"),
                new XElement(ca + "field2", "another test"));
    }
}

Solution 2:

Try this code:

string prefix = element.GetPrefixOfNamespace(element.Name.NamespaceName);
string name = String.Format(prefix == null ? "{1}" : "{0}:{1}", prefix, element.Name.LocalName);`