IConfigurationSectionHandler example

gistfile1.cs

public class ConfigurationHandler : IConfigurationSectionHandler
{
	/// <summary>
	/// Creates a <see cref="Settings"/> object from the configuration file.
	/// </summary>
	/// <seealso cref="Settings"/>
	public object Create(object parent, object configContext, System.Xml.XmlNode section)
	{
		if (section == null)
			throw new ArgumentNullException("'section' is null. Check your app.config or web.config exists and is valid.");
		try
		{
			Settings settings = new Settings();
			// Security
			XmlNode node = section.SelectSingleNode("//security");
			if (node != null)
				Settings.Security = (node.Attributes["enabled"].Value == "true");
			else
				throw new Exception("No security node could be found in the web/app.config");
			// Username
			node = section.SelectSingleNode("//username");
			if (node != null)
				settings.Username = node.Value;
			else
				throw new Exception("No username could be found in the web/app.config");
			return settings;
		}
		catch (XPathException ex)
		{
			// Catch From SelectSingleNode,SelectNodes
			throw new Exception("XPathException caught when reading config file", ex);
		}
	}
}

public class Settings
{
	public bool Security { get; set; }
	public string Username { get; set; }
}