C# Tutorial 10.3 :LINQ to XML

LINQ to XML is a powerful feature in C# that allows you to query and manipulate XML documents using LINQ (Language Integrated Query). Let's break down the tutorial into several steps.

Step 1: Introduction to LINQ to XML

using System;
using System.Linq;
using System.Xml.Linq;
class Program
{
    static void Main()
    {
        // Create a sample XML document
        XElement xmlTree = new XElement("Root",
            new XElement("Element1", "Value1"),
            new XElement("Element2", "Value2"),
            new XElement("Element3", "Value3")
        );
        // Display the XML document
        Console.WriteLine("Original XML:");
        Console.WriteLine(xmlTree);
        // LINQ to XML queries go here
        Console.ReadLine(); // Keep console window open in debug mode
    }
}

Step 2: Basic LINQ to XML Queries

// Query to get all elements with the name "Element2"
var element2 = xmlTree.Elements("Element2");
Console.WriteLine("\nQuery - Elements with name 'Element2':");
foreach (var element in element2)
{
    Console.WriteLine(element);
}
// Query to get the value of Element1
var valueOfElement1 = xmlTree.Element("Element1")?.Value;
Console.WriteLine("\nQuery - Value of Element1:");
Console.WriteLine(valueOfElement1);

Step 3: Creating and Modifying XML with LINQ

// Add a new element to the XML document
xmlTree.Add(new XElement("Element4", "Value4"));
// Modify the value of Element2
var elementToModify = xmlTree.Element("Element2");
if (elementToModify != null)
{
    elementToModify.Value = "NewValue";
}
Console.WriteLine("\nModified XML:");
Console.WriteLine(xmlTree);

Step 4: Filtering with LINQ to XML

// Query to get elements with values containing "Value"
var elementsWithValue = xmlTree.Elements().Where(e => e.Value.Contains("Value"));
Console.WriteLine("\nQuery - Elements with values containing 'Value':");
foreach (var element in elementsWithValue)
{
    Console.WriteLine(element);
}

Step 5: Loading XML from a File

// Load XML from a file
XDocument loadedXml = XDocument.Load("path/to/your/file.xml");
Console.WriteLine("\nLoaded XML from file:");
Console.WriteLine(loadedXml);

Step 6: Saving XML to a File

// Save XML to a file
xmlTree.Save("path/to/your/outputfile.xml");
Console.WriteLine("\nXML saved to file.");

This tutorial covers the basics of LINQ to XML in C#. Feel free to expand upon this foundation and explore more advanced features as needed for your specific use case.