Creating a XML Document from scratch without using a file in C#

Creating a XML Document from scratch without using a file in C#

April 4, 2007

One thing that’s annoying is that majority of the XML example assumes that you are loading an XML document from a file, so here’s a simple code example for generating it entirely in memory.

// Create the xml document containe
XmlDocument doc = new XmlDocument(); // Create the XML Declaration, and append it to XML document
XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", null, null);
doc.AppendChild(dec); // Create the root element
XmlElement root = doc.CreateElement("Library");
doc.AppendChild(root);

// Create Books
// Note that to set the text inside the element,
// you use .InnerText instead of .Value (which will throw an exception).
// You use SetAttribute to set attribute
XmlElement book = doc.CreateElement("Book");
book.SetAttribute("BookType", "Hardcover");
XmlElement title = doc.CreateElement("Title");
title.InnerText = "Door Number Three";
XmlElement author = doc.CreateElement("Author");
author.InnerText = "O'Leary, Patrick";
book.AppendChild(title);
book.AppendChild(author);
root.AppendChild(book);

book = doc.CreateElement("Book");
book.SetAttribute("BookType", "Paperback");
title = doc.CreateElement("Title");
title.InnerText = "Lord of Light";
author = doc.CreateElement("Author");
author.InnerText = "Zelanzy, Roger";
book.AppendChild(title);
book.AppendChild(author);
root.AppendChild(book);

string xmlOutput = doc.OuterXml;

The same code but using an XMLWriter to a memory stream.


XmlWriterSettings wSettings = new XmlWriterSettings();
wSettings.Indent = true;
MemoryStream ms = new MemoryStream();
XmlWriter xw = XmlWriter.Create(ms, wSettings); // Write Declaration
xw.WriteStartDocument();

// Write the root node
xw.WriteStartElement("Library");

// Write the books and the book elements
xw.WriteStartElement("Book");
xw.WriteStartAttribute("BookType");
xw.WriteString("Hardback");
xw.WriteEndAttribute();

xw.WriteStartElement("Title");
xw.WriteString("Door Number Three");
xw.WriteEndElement();
xw.WriteStartElement("Author");
xw.WriteString("O'Leary, Patrick");
xw.WriteEndElement();

xw.WriteEndElement();

// Write another book
xw.WriteStartElement("Book");
xw.WriteStartAttribute("BookType");
xw.WriteString("Paperback");
xw.WriteEndAttribute();

xw.WriteStartElement("Title");
xw.WriteString("Lord of Light");
xw.WriteEndElement();
xw.WriteStartElement("Author");
xw.WriteString("Zelanzy, Roger");
xw.WriteEndElement();

xw.WriteEndElement();

// Close the document
xw.WriteEndDocument();

// Flush the write
xw.Flush();

Byte[] buffer = new Byte[ms.Length];
buffer = ms.ToArray();
string xmlOutput = System.Text.Encoding.UTF8.GetString(buffer);

 

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Create a New XML File Using XmlDocument

Here's the XML File:

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

<CategoryList>

  <Category ID="01">

    <MainCategory>XML</MainCategory>

    <Description>This is a list my XML articles.</Description>

    <Active>true</Active>

  </Category>

</CategoryList>

Here's the code:

<%@ Import Namespace="System.Data" %>

<%@ Import Namespace="System.Xml" %>

<%@ Page Language="C#" Debug="true" %>


<script  runat="server">

void Page_Load(object sender, System.EventArgs e){

    if(!Page.IsPostBack){

        XmlDocument xmlDoc = new XmlDocument();



        // Write down the XML declaration

        XmlDeclaration xmlDeclaration = xmlDoc.CreateXmlDeclaration("1.0","utf-8",null); 


        // Create the root element

        XmlElement rootNode  = xmlDoc.CreateElement("CategoryList");

        xmlDoc.InsertBefore(xmlDeclaration, xmlDoc.DocumentElement); 

        xmlDoc.AppendChild(rootNode);


        // Create a new <Category> element and add it to the root node

        XmlElement parentNode  = xmlDoc.CreateElement("Category");


        // Set attribute name and value!

        parentNode.SetAttribute("ID", "01");


        xmlDoc.DocumentElement.PrependChild(parentNode);


        // Create the required nodes

        XmlElement mainNode  = xmlDoc.CreateElement("MainCategory");

        XmlElement descNode  = xmlDoc.CreateElement("Description");

        XmlElement activeNode  = xmlDoc.CreateElement("Active");


        // retrieve the text 

        XmlText categoryText= xmlDoc.CreateTextNode("XML");

        XmlText descText  = xmlDoc.CreateTextNode("This is a list my XML articles.");

        XmlText activeText  = xmlDoc.CreateTextNode("true");


        // append the nodes to the parentNode without the value

        parentNode.AppendChild(mainNode);

        parentNode.AppendChild(descNode);

        parentNode.AppendChild(activeNode);


        // save the value of the fields into the nodes

        mainNode.AppendChild(categoryText);

        descNode.AppendChild(descText);

        activeNode.AppendChild(activeText);


        // Save to the XML file

        xmlDoc.Save( Server.MapPath("categories.xml"));


        Response.Write("XML file created");

    }

}

</script>