MSDN Documentation

Core XML Namespaces

The primary namespaces for XML manipulation in .NET are:

• System.Xml: Provides fundamental classes for XML processing, including reading, writing, and parsing XML.
• System.Xml.Linq: Offers a more modern and object-oriented approach to XML manipulation with LINQ to XML.
• System.Xml.Schema: Enables validation of XML documents against XML Schema Definitions (XSD).
• System.Xml.Serialization: Facilitates the serialization and deserialization of .NET objects to and from XML.

Key Classes and Concepts

XmlReader and XmlWriter

XmlReader and XmlWriter provide forward-only, read-only access to XML data. They are highly performant and suitable for processing large XML files.

// Example of XmlReader
using (XmlReader reader = XmlReader.Create("mydata.xml"))
{
    while (reader.Read())
    {
        switch (reader.NodeType)
        {
            case XmlNodeType.Element:
                Console.WriteLine($"Start Element: {reader.Name}");
                break;
            case XmlNodeType.Text:
                Console.WriteLine($"Text: {reader.Value}");
                break;
            case XmlNodeType.EndElement:
                Console.WriteLine($"End Element: {reader.Name}");
                break;
        }
    }
}
                    

XmlDocument

The XmlDocument class represents an XML document as a Document Object Model (DOM) tree. This allows for random access and modification of the XML structure.

XmlDocument doc = new XmlDocument();
doc.Load("mydata.xml");
XmlNodeList nodes = doc.GetElementsByTagName("book");
foreach (XmlNode node in nodes)
{
    Console.WriteLine(node.InnerText);
}
                    

LINQ to XML (System.Xml.Linq)

LINQ to XML provides a powerful and concise way to query and manipulate XML documents using Language Integrated Query (LINQ).

XDocument doc = XDocument.Load("mydata.xml");
var bookTitles = from book in doc.Descendants("book")
                 select book.Element("title").Value;

foreach (var title in bookTitles)
{
    Console.WriteLine(title);
}
                    

XML Schema (XSD) Validation

System.Xml.Schema allows you to validate XML documents against XSD schemas to ensure data integrity and conformity.

XmlReader reader = XmlReader.Create("data.xml");
reader.MoveToContent();

XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add(null, "schema.xsd");

// Set options for validation
XmlReaderSettings settings = new XmlReaderSettings();
settings.Schemas = schemas;
settings.ValidationType = ValidationType.Schema;
settings.ValidationEventHandler += new ValidationEventHandler(ValidationCallBack);

XmlReader validatingReader = XmlReader.Create(reader, settings);

while (validatingReader.Read()) { } // Process the validated document

void ValidationCallBack(object sender, ValidationEventArgs args)
{
    if (args.Severity == XmlSeverityType.Error)
    {
        Console.WriteLine($"Validation Error: {args.Message}");
    }
}