C# - XmlTextWriter - Dot Net Perls

XmlTextWriter. This type renders XML data to a string. This string remains in the memory of the C# program. We use an underlying buffer—in this case, a StringWriter instance.

First, this program includes the System.Xml and System.IO namespaces. These are for the XmlTextWriter and StringWriter. The program creates an array of 4 Tuple instances.

StringWriter

Tuple

Info The StringWriter is used as a backing store for the XmlTextWriter. XmlTextWriter to the StringWriter instance you passed to it.

Next We see the WriteStartDocument and WriteStateElement methods. These begin the XML document and then begin an element.

Note When you pass a string to WriteStartElement, the XmlTextWriter then will know the element tag you are writing.

Finally We see a foreach loop that enumerates the array of Tuple instances. In each iteration, we write an Employee element.

foreach

using System; using System.IO; using System.Xml; class Program { static void Main() { // Create an array of four Tuples. var array = new Tuple<int, string, string, int>[4]; array[0] = new Tuple<int, string, string, int>(1, "David", "Smith", 10000); array[1] = new Tuple<int, string, string, int>(3, "Mark", "Drinkwater", 30000); array[2] = new Tuple<int, string, string, int>(4, "Norah", "Miller", 20000); array[3] = new Tuple<int, string, string, int>(12, "Cecil", "Walker", 120000); // Use StringWriter as backing for XmlTextWriter. using (StringWriter str = new StringWriter()) using (XmlTextWriter xml = new XmlTextWriter(str)) { // Root. xml.WriteStartDocument(); xml.WriteStartElement("List"); xml.WriteWhitespace("\n"); // Loop over Tuples. foreach (var element in array) { // Write Employee data. xml.WriteStartElement("Employee"); xml.WriteElementString("ID", element.Item1.ToString()); xml.WriteElementString("First", element.Item2); xml.WriteWhitespace("\n "); xml.WriteElementString("Last", element.Item3); xml.WriteElementString("Salary", element.Item4.ToString()); xml.WriteEndElement(); xml.WriteWhitespace("\n"); } // End. xml.WriteEndElement(); xml.WriteEndDocument(); // Result is a string. string result = str.ToString(); Console.WriteLine("Length: {0}", result.Length); Console.WriteLine("Result: {0}", result); } } }

Length: 441 Result: <?xml version="1.0" encoding="utf-16"?><List> <Employee><ID>1</ID><First>David</First> <Last>Smith</Last><Salary>10000</Salary></Employee> <Employee><ID>3</ID><First>Mark</First> <Last>Drinkwater</Last><Salary>30000</Salary></Employee> <Employee><ID>4</ID><First>Norah</First> <Last>Miller</Last><Salary>20000</Salary></Employee> <Employee><ID>12</ID><First>Cecil</First> <Last>Walker</Last><Salary>120000</Salary></Employee> </List>

After constructing XmlTextWriter with a backing stream, you must use WriteStartDocument. All Start methods must be matched by End methods such as WriteEndDocument.