Non-Stopping Upgradable Service Framework

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ClassContract
{
    public class Component : IComponent
    {
        #region IComponent Members

        public IList<IComponent> DownstreamComponents { get; set; }
        public bool IsUpgradable { get; set; }
        public string Name { get; set; }
        public string Downstreams { get; set; }

        public virtual bool Start() { return true; }
        public virtual bool Stop() { return true; }

        public virtual bool DoBusiness(object obj = null)
        {
            Console.WriteLine("[{0}] DoBusiness, obj={1}", this.Name, obj);

            OnAfterBusiness(obj);

            return true;
        }

        protected virtual void OnAfterBusiness(object obj)
        {
            if (this.AfterBusiness != null)
            {
                this.AfterBusiness(this, new ComponentDataEventArgs(obj));
            }
        }

        public virtual event EventHandler<ComponentDataEventArgs> AfterBusiness;

        #endregion
    }
}