Provider Pattern

using System;
using System.Configuration;
using System.Configuration.Provider;
using System.Web.Configuration;

namespace ConfigActivities {
    public class MyProviderManager {
        //Initialization related variables and logic
        private static bool isInitialized = false;
        private static Exception initializationException;

        private static object initializationLock = new object();

        static MyProviderManager() {
            Initialize();
            }

        private static void Initialize() {

            try {
                //Get the feature's configuration info
                MyProviderConfiguration qc =
                    (MyProviderConfiguration)ConfigurationManager.GetSection("MyProvider");

                if (qc.DefaultProvider == null || qc.Providers == null || qc.Providers.Count < 1)
                    throw new ProviderException("You must specify a valid default provider.");

                //Instantiate the providers
                providerCollection = new MyProviderProviderCollection();
                ProvidersHelper.InstantiateProviders(qc.Providers, providerCollection, typeof(MyProviderProvider));
                providerCollection.SetReadOnly();
                defaultProvider = providerCollection[qc.DefaultProvider];
                if (defaultProvider == null) {
                    throw new ConfigurationErrorsException(
                        "You must specify a default provider for the feature.",
                        qc.ElementInformation.Properties["defaultProvider"].Source,
                        qc.ElementInformation.Properties["defaultProvider"].LineNumber);
                    }
                }
            catch (Exception ex) {
                initializationException = ex;
                isInitialized = true;
                throw ex;
                }

            isInitialized = true; //error-free initialization
            }

        //Public feature API
        private static MyProviderProvider defaultProvider;
        private static MyProviderProviderCollection providerCollection;

        public static MyProviderProvider Provider {
            get {
                return defaultProvider;
                }
            }

        public static MyProviderProviderCollection Providers {
            get {
                return providerCollection;
                }
            }

        public static string DoWork() {
            return Provider.DoWork();
            }
        }
    }