SharePoint 2010 AppPool DropDownList

While playing around trying to figure out how SharePoint 2010 populates that wonderful drop down list of AppPools, as seen in the screeshot just below, I noticed that all the classes it uses are marked internal sealed.

Since I wanted to learn more about how this control worked, I decided to use reflector to poke around. Here is the small amount of info I discovered of the items in the list:

And here is the code that produces that output.

public class Program
    {
        static void Main(string[] args)
        {
            DiscoverAppPools();
        }

        public class AppPoolInfo
        {
            public string Name { get; set; }
            public string IISObjectName { get; set; }
            public IdentityType IdentityType { get; set; }
            public string Username { get; set; }
        }

        //Queries the farm to find the list of AppPools to display in an IisWebServiceApplicationPoolSection control
        public static void DiscoverAppPools()
        {
            List discoveredAppPools = new List();

            Assembly assembly = Assembly.Load("Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c");
            Type typeSPIisWebServiceSettings = assembly.GetType("Microsoft.SharePoint.Administration.SPIisWebServiceSettings");

            /*
             * There are a few other interesting properties that we aren't pulling, but might be handy to peek at.
             * oSettings.IisSiteName
             * oSettings.HttpPort
             * oSettings.HttpsPort
             * oAppPool.Id
             * oAppPool.Status
             * oAppPool.ProcessAccount.SecurityIdentifier.Value
             */
            object oSettings = SPFarm.Local.GetObject("SharePoint Web Services", SPFarm.Local.Id, typeSPIisWebServiceSettings);
            if (oSettings != null)
            {
                Type typeSPIisWebServiceApplicationPoolCollection = assembly.GetType("Microsoft.SharePoint.Administration.SPIisWebServiceApplicationPoolCollection");
                ConstructorInfo constructor = typeSPIisWebServiceApplicationPoolCollection.GetConstructor(
                    BindingFlags.NonPublic | BindingFlags.Instance, null, new Type[] { typeSPIisWebServiceSettings }, null);

                object oAppPools = null;                
                if (constructor != null)
                {
                    oAppPools = constructor.Invoke(new object[] {oSettings});
                    if (oAppPools != null)
                    {
                        Type typeSPIisWebServiceApplicationPool = assembly.GetType("Microsoft.SharePoint.Administration.SPIisWebServiceApplicationPool");

                        IEnumerable appPools = (IEnumerable)oAppPools;
                        if (appPools != null)
                        {
                            IEnumerator enumerator = appPools.GetEnumerator();
                            while (enumerator.MoveNext())
                            {
                                AppPoolInfo api = new AppPoolInfo();

                                object oAppPool = enumerator.Current;
                                PropertyInfo piName = typeSPIisWebServiceApplicationPool.GetProperty("Name");
                                if (piName != null)
                                {
                                    api.Name = (string)piName.GetValue(oAppPool, null);
                                }

                                PropertyInfo piIisObjectName = typeSPIisWebServiceApplicationPool.GetProperty("IisObjectName", BindingFlags.Instance | BindingFlags.NonPublic);
                                if (piIisObjectName != null)
                                {
                                    api.IISObjectName = (string)piIisObjectName.GetValue(oAppPool, null);
                                }

                                //not terribly useful; really only gives a SID. Maybe good if you wanted their credentials as a SecureString
                                //PropertyInfo piProcessAccount = typeSPIisWebServiceApplicationPool.GetProperty("ProcessAccount");
                                //if (piProcessAccount != null)
                                //{
                                //    object o = piProcessAccount.GetValue(oAppPool, null);
                                //}

                                PropertyInfo piCurrentIdentityType = typeSPIisWebServiceApplicationPool.GetProperty("CurrentIdentityType", BindingFlags.Instance | BindingFlags.NonPublic);
                                if (piCurrentIdentityType != null)
                                {
                                    api.IdentityType = (IdentityType)piCurrentIdentityType.GetValue(oAppPool, null);
                                }

                                PropertyInfo piManagedAccount = typeSPIisWebServiceApplicationPool.GetProperty("ManagedAccount", BindingFlags.Instance | BindingFlags.NonPublic);
                                if (piManagedAccount != null)
                                {
                                    object oManagedAccount = piManagedAccount.GetValue(oAppPool, null);
                                    if (oManagedAccount != null)
                                    {
                                        PropertyInfo piUsername = oManagedAccount.GetType().GetProperty("Username");
                                        if (piUsername != null)
                                        {
                                            api.Username = (string)piUsername.GetValue(oManagedAccount, null);
                                        }
                                    }
                                }

                                discoveredAppPools.Add(api);
                            }
                        }
                    }
                }
            }

            Console.WriteLine("SharePoint knows about the following AppPools");
            foreach(AppPoolInfo api in discoveredAppPools)
            {
                Console.WriteLine("\nAppPool: {0}", api.Name);
                Console.WriteLine("  IIS Object Name: {0}", api.IISObjectName);
                Console.WriteLine("  Identity Type: {0}", api.IdentityType);
                Console.WriteLine("  Username: {0}", api.Username );
            }
        }
    }