using System;

using System.Xml.Linq;

​

public class Program

{

    public static void Main()

    {

        XNamespace ss = "urn:schemas-microsoft-com:office:spreadsheet";

​

        var document = new XDocument(

            new XDeclaration("1.0", null, null),

            new XProcessingInstruction("mso-application", "progid=\"Excel.Sheet\""),

            new XElement(ss + "Workbook",

                new XAttribute("xmlns", "urn:schemas-microsoft-com:office:spreadsheet"),

                new XAttribute(XNamespace.Xmlns + "o", "urn:schemas-microsoft-com:office:office"),

                new XAttribute(XNamespace.Xmlns + "x", "urn:schemas-microsoft-com:office:excel"),

                new XAttribute(XNamespace.Xmlns + "ss", "urn:schemas-microsoft-com:office:spreadsheet"),

                new XAttribute(XNamespace.Xmlns + "html", "http://www.w3.org/TR/REC-html40"),

                new XElement(ss + "Styles",

                    new XElement(ss + "Style",

                        new XAttribute("ID", "Default")

                        )

                    ),

                new XElement(ss + "Worksheet",

                    new XAttribute(ss + "Name", "Worksheet Name"),

                    new XElement(ss + "Table",

                        new XElement(ss + "Row",

                            new XElement(ss + "AutoFitHeight", 0),

                            new XElement(ss + "Cell",

                                new XElement(ss + "Data",

                                    new XAttribute(ss + "Type", "String"),

                                    "Value")

                                )

                            )

​

                        )

                    )

                )

            );

​

        Console.WriteLine(document);

    }

}