ConfigurationElement.LockItem Property

// Show how to set LockItem
// It adds a new UrlConfigElement to 
// the collection.
static void LockItem()
{
    string name = "Contoso";
    string url = "http://www.contoso.com/";
    int port = 8080;

    try
    {
        // Get the current configuration file.
        System.Configuration.Configuration config =
            ConfigurationManager.OpenExeConfiguration(
            ConfigurationUserLevel.None);

        // Get the MyUrls section.
        UrlsSection myUrls =
           config.Sections["MyUrls"] as UrlsSection;


        // Create the new  element.
        UrlConfigElement newElement =
            new UrlConfigElement(name, url, port);

        // Set its lock.
        newElement.LockItem = true;

        // Save the new element to the 
        // configuration file.
        if (!myUrls.ElementInformation.IsLocked)
        {

            myUrls.Urls.Add(newElement);

            config.Save(ConfigurationSaveMode.Full);

            // This is used to obsolete the cached 
            // section and read the updated 
            // bersion from the configuration file.
            ConfigurationManager.RefreshSection("MyUrls");
        }
        else
            Console.WriteLine(
                "Section was locked, could not update.");

    }
    catch (ConfigurationErrorsException e)
    {
        Console.WriteLine("[LockItem: {0}]",
            e.ToString());
    }

}