C#

public IApplicationPrivilegeCollection GetAllUserPrivileges(string userName)
        {
            Precondition.NotNullArgument(userName, "userName");

            IDatabaseInfoCollection databaseInfoCollection = _databaseInfoRepository.getAllDatabases();
            IApplicationPrivilegeCollection applicationPrivilegeCollection = new ApplicationPrivilegeCollection();
            int applicationCount = 0;
            //For each program get user priv information
            foreach (IDatabaseInfo databaseInfo in databaseInfoCollection)
            {
                //for each priv check if they have privs
                BackgroundWorker worker = new BackgroundWorker();
                IApplicationPrivilege list = new ApplicationPrivilege();

                worker.DoWork += delegate(object sender, DoWorkEventArgs e)
                                     {
                                         worker = sender as BackgroundWorker;
                                         list = GetUserPrivilege(userName, (IDatabaseInfo)e.Argument);
                                     }
                    ;
                worker.RunWorkerCompleted += delegate(object sender, RunWorkerCompletedEventArgs e)
                                                 {
                                                     applicationPrivilegeCollection.Add(list);
                                                     applicationCount++;
                                                 };
                worker.RunWorkerAsync(databaseInfo);
            }

            //Timer timer = new Timer();
            //timer.Interval = 250;
            //timer.Elapsed += delegate
            //                     {
            //                         if(applicationCount == databaseInfoCollection.Count)
            //                         {
            //                             timer.Stop();
            //                             return;
            //                         }
            //                     };
            //timer.Start();

            return applicationPrivilegeCollection;
        }

using System;
using System.IO;
using System.Collections.Generic;
using System.Text;
using System.Runtime.Serialization;
using System.Xml;
using System.Runtime.Serialization.Formatters.Soap;

namespace Serialization
	{
	// Create a class to include in the list
	[Serializable]
	public class MyObject:ISerializable
		{
		public Int32 idx=0;

		public MyObject(Int32 i)
			{
			idx=i;
			}

		public virtual void GetObjectData(SerializationInfo info,StreamingContext context)
			{
			info.AddValue("Idx",idx);
			}
		}

	// The objectlist consists of a list of MyObjects
	[Serializable]
	class ObjectList: ISerializable
		{
		public List<MyObject> TheList;

		public ObjectList()
			{
			TheList=new List<MyObject>(10);
			MyObject tmp=new MyObject(1);
			TheList.Add(tmp);
			tmp=new MyObject(2);
			TheList.Add(tmp);
			}

		public virtual void GetObjectData(SerializationInfo info,StreamingContext context)
			{
			Int32 i=0;

			for(i=0;i<2;i++)
				{
				if(TheList[i]!=null)
					{
					// Serialize a MyObject contained in TheList
					// This does not work for the second occurrence of MyObject
					TheList[i].GetObjectData(info,context);
					}
				}
			}
		}

	class Program
		{
		static void Main(string[] args)
			{
			ObjectList MyObjectList=new ObjectList();
			FileStream WriteStream=new FileStream("test.xml",FileMode.Create); 
			SoapFormatter bfor=new SoapFormatter();
			bfor.Serialize(WriteStream,MyObjectList);
			}
		}
	}