Reading data from XML [duplicate]

I don't think you can "legally" load only part of an XML file, since then it would be malformed (there would be a missing closing element somewhere).

Using LINQ-to-XML, you can do var doc = XDocument.Load("yourfilepath"). From there its just a matter of querying the data you want, say like this:

var authors = doc.Root.Elements().Select( x => x.Element("Author") );

HTH.

EDIT:

Okay, just to make this a better sample, try this (with @JWL_'s suggested improvement):

using System;using System.Xml.Linq;namespace ConsoleApplication1 {    class Program {        static void Main( string[] args )  {            XDocument doc = XDocument.Load( "XMLFile1.xml" );            var authors = doc.Descendants( "Author" );            foreach ( var author in authors ) {                Console.WriteLine( author.Value );            }            Console.ReadLine();        }    }}

You will need to adjust the path in XDocument.Load() to point to your XML file, but the rest should work. Ask questions about which parts you don't understand.

as per @Jon Skeet 's comment, you should use a XmlReader only if your file is very big. Here's how to use it.Assuming you have a Book class

public class Book {    public string Title {get; set;}    public string Author {get; set;}}

you can read the XML file line by line with a small memory footprint, like this:

public static class XmlHelper {    public static IEnumerable<Book> StreamBooks(string uri) {        using (XmlReader reader = XmlReader.Create(uri)) {            string title = null;            string author = null;            reader.MoveToContent();            while (reader.Read()) {                if (reader.NodeType == XmlNodeType.Element                    && reader.Name == "Book") {                    while (reader.Read()) {                        if (reader.NodeType == XmlNodeType.Element &&                            reader.Name == "Title") {                            title = reader.ReadString();                            break;                        }                    }                    while (reader.Read()) {                        if (reader.NodeType == XmlNodeType.Element &&                            reader.Name == "Author") {                            author =reader.ReadString();                            break;                        }                    }                    yield return new Book() {Title = title, Author = author};                }            }               }    }

Example of usage:

string uri = @"c:\test.xml"; // your big XML fileforeach (var book in XmlHelper.StreamBooks(uri)) {    Console.WriteLine("Title, Author: {0}, {1}", book.Title, book.Author);  }

Alternatively, you can use XPathNavigator:

XmlDocument doc = new XmlDocument();doc.LoadXml(xml);XPathNavigator navigator = doc.CreateNavigator();string books = GetStringValues("Books: ", navigator, "//Book/Title");string authors = GetStringValues("Authors: ", navigator, "//Book/Author");

..

/// <summary>/// Gets the string values./// </summary>/// <param name="description">The description.</param>/// <param name="navigator">The navigator.</param>/// <param name="xpath">The xpath.</param>/// <returns></returns>private static string GetStringValues(string description,                                      XPathNavigator navigator, string xpath) {    StringBuilder sb = new StringBuilder();    sb.Append(description);    XPathNodeIterator bookNodesIterator = navigator.Select(xpath);    while (bookNodesIterator.MoveNext())       sb.Append(string.Format("{0} ", bookNodesIterator.Current.Value));    return sb.ToString();}