C# Example: XML Property File

    public class MyProperties
    {
        private static readonly ILog log =
        LogManager.GetLogger(typeof(MyProperties));
 
        private const string propDir = "Properties";
        private const string myprofile = propDir + "/fcx.xml";
        private Dictionary<string, string> myprops = null;
 
        // Singleton
        private static MyProperties instance;
        private MyProperties() { }
        public static MyProperties Instance
        {
            get
            {
                if (instance == null)
                {
                    instance = new MyProperties();
                    instance.LoadProperties();
                }
                return instance;
            }
        }
 
        // Find value from key
        public string FindValue(string key)
        {
            return this.FindValue(key, this.myprops);
        }
 
        // =================================================== Common
        private string FindValue(string key, Dictionary<string, string> props)
        {
            foreach (string k in props.Keys)
            {
                if (key.Equals(k, StringComparison.InvariantCultureIgnoreCase))
                {
                    return props[key];
                }
            }
            return null;
        }
 
        private void LoadProperties()
        {
            // Load once
            if (myprops == null)
            {
                myprops = new Dictionary<string, string>();
                this.LoadProperties(myprofile, myprops);
            }
        }
 
        private void LoadProperties(string file, Dictionary<string, string> props)
        {
            if (!File.Exists(file))
            {
                log.ErrorFormat("Property file not found: {0}", myprofile);
                Environment.Exit(0);
            }
 
            XmlDocument doc = new XmlDocument();
            doc.Load(file);
            foreach (XmlNode c in doc.ChildNodes)
            {
                if (c.Name.Equals("Settings"))
                {
                    foreach (XmlNode n in c.ChildNodes)
                    {
                        if (n.Name.Equals("add", 
                            StringComparison.InvariantCultureIgnoreCase))
                        {
                            props.Add(
                                n.Attributes["key"].Value,
                                n.Attributes["value"].Value);
                        }
                    }
                }
            }
        }
    }

    [TestClass]
    public class UnitTest1
    {
        private static readonly ILog log = 
            LogManager.GetLogger(typeof(UnitTest1));
 
        [TestMethod]
        public void TestMethod1()
        {
            string k = "prop1";
            string v = MyProperties.Instance.FindValue(k);
            log.InfoFormat("Found value {0} for key {1}.", v, k);
        }
    }