Question

i have the following xml file

<?xml version="1.0" encoding="utf-8"?> 
<Users>
    <User>
        <Name>John Smith</Name>
        <test>
            <Date>23.05.2011</Date>
            <points>33</points>
        </test>
        <test>
            <Date>22.06.2011</Date>
            <points>29</points>
        </test>
    </User>
</Users>

and i would like to use linq to extract the dates and the points of the tests where username is “John Smith”..

how would i build my linq ?

i have done the following, but is not working as i wish :

XElement main = XElement.Load(@"users.xml");

string t = "John Smith";
var v = from user in main.Elements("User")
        where t == users.Element("Name").Value
        select users;

MessageBox.Show(v.First().Element("Date").Value.ToString()); 

Answer 1

I’m not sure what format you want the output to be, but this samples code should get the date and points. This projects the results into an anonymous type:

class Program
{
    static void Main(string[] args)
    {
        XElement main = XElement.Load(@"users.xml");

        var results = main.Descendants("User")
            .Descendants("Name")
            .Where(e => e.Value == "John Smith")
            .Select(e => e.Parent)
            .Descendants("test")
            .Select(e => new { date = e.Descendants("Date").FirstOrDefault().Value, points = e.Descendants("points").FirstOrDefault().Value });

        foreach (var result in results)
            Console.WriteLine("{0}, {1}", result.date, result.points);
        Console.ReadLine();
    }
}

And the output is:

23.05.2011, 33
22.06.2011, 29