Question

I have a XML document and it is contains some date data like:

<Message>
<messagetext>Testing purpose only</messagetext>
<date>05.02.2010</date>
</Message>

I want them sorted with a XPath key, how can I get it?

Answer 1

You can do it using LINQ to XML as follows. I assume you are using the format MM.dd.yyyy, but this can easily be changed if you want:

using System;
using System.Linq;
using System.Xml.Linq;

public class Message
{
    public string Text { get; set; }
    public DateTime Date { get; set; }
}

class Program
{
    static void Main(string[] args)
    {
        XDocument doc = XDocument.Load("input.xml");
        var messages = doc.Descendants("Message")
            .Select(element => new Message
            {
                Text = element.Element("messagetext").Value,
                Date = DateTime.ParseExact(element.Element("date").Value, "MM.dd.yyyy", null)
            }).OrderBy(message => message.Date);
        foreach (Message message in messages)
        {
            Console.WriteLine("{0} : {1}", message.Date, message.Text);
        }
    }
}

Results:

02-05-2010 00:00:00 : Test1
17-05-2010 00:00:00 : Test2
22-05-2010 00:00:00 : Test3

Test data I used:

<xml>
  <Message>
    <messagetext>Test1</messagetext>
    <date>05.02.2010</date>
  </Message>
  <Message>
    <messagetext>Test3</messagetext>
    <date>05.22.2010</date>
  </Message>
  <Message>
    <messagetext>Test2</messagetext>
    <date>05.17.2010</date>
  </Message>
</xml>