LINQ to XML to retrieve an element value by its attribute

Introduction

This article tells us how to retrieve a value of an element depending on the attribute value.

The Scenario

I have a web site where I need to read some data as static but I want to be able to update it any time, so I decided to read it from an XML file and use LINQ to XML. After some time and a lot of searching here and there, I had a better understanding of the idea and so I decided to share it with every one.

Using the Code

We will make an XML file and a class to get the data from it:

1. The XML file "Actions.xml":
XML

<?xml version="1.0" encoding="utf-8" ?>
<Actions>
<Action id="SignIn">1</Action>
<Action id="SignOut">2</Action>
<Action id="Open">3</Action>
</Actions>

2. The class "Actions.cs":

We will make the class constructor the one which gets the data to our variables in the class.

C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Xml.Linq;

public class Actions
{
    int signIn, signOut, open;
    public int SignIn
    {
        get { return signIn; }
    }

    public Actions()
    {
        XElement xe = XElement.Load(@"C:\Users\ADELOooO\Documents\
        Visual Studio 10\WebSites\LinQReadXML\Actions.xml");
        var x = from a in xe.Elements("Action")
          Where a.Attribute("id").Value == "SignIn"
          select a.Value;
        signIn = int.Parse(x.First().ToString());
    }
}

We have used the signin variable as an example above, but you can use it with them all.

3. The code behind the webpage to call the method is shown here:
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        Actions a = new Actions();
        TextBox1.Text = a.SignIn.ToString();
    }
}

Points of Interest

I used VSTS 10 beta to create this project. I hope that you find it helpful.