非同期プロセスがファイルの内容を読み込む

class Class1
    {
        public delegate int AsyncEventHandler(int a);
        static List<string> l = new List<string>();
        static int ps = 1000;
        static long end = 0;
        static long start = 0;

        void Event1()
        {
            Console.WriteLine("Event1 Start");
            System.Threading.Thread.Sleep(2000);
            Console.WriteLine("Event1 End");
        }

        int Event2(int pi)
        {
            Console.WriteLine("Event2 Start  " + pi + " ");

            for (int i = 0; i < ps; i++)
            {
                Console.WriteLine(l[(pi - 1) * ps + i]);
            }
            Console.WriteLine("Event2 End  " + pi + " ");
            return pi;
        }

        void CallbackMethod(IAsyncResult ar)
        {
            var del = (AsyncEventHandler)ar.AsyncState;
            var a = del.EndInvoke(ar);
            Console.WriteLine("  " + a + "   ------------------ ：" + (end - start).ToString() + "-------------------------");
            //((AsyncEventHandler)ar.AsyncState).EndInvoke(ar);
        }


        [STAThread]
        static void Main(string[] args)
        {
            Class1 c = new Class1();
            Console.WriteLine("ready");
            start = DateTime.Now.Ticks;

            //AsyncEventHandler asy = new AsyncEventHandler(c.Event1);
            //IAsyncResult ia = asy.BeginInvoke(new AsyncCallback(c.CallbackMethod), asy);
            //c.Event2();
            //asy.EndInvoke(ia);



            using (StreamReader sr = new StreamReader(@"R:\123.txt", Encoding.Default))
            {
                AsyncEventHandler asy = new AsyncEventHandler(c.Event2);
                var line = sr.ReadLine();
                while (line != null)
                {
                    l.Add(line);
                    if (l.Count % ps == 0 && l.Count > 0)
                    {
                        IAsyncResult ia = asy.BeginInvoke(l.Count / ps, new AsyncCallback(c.CallbackMethod), asy);
                    }
                    //Console.WriteLine(line);//=144218750
                    //Task<int>.Factory.FromAsync(asy.BeginInvoke, asy.EndInvoke, (l.Count / ps), null).ContinueWith(o => Console.WriteLine(string.Format(" :{0}", o.Result)));
                    line = sr.ReadLine();
                }
            }
            //WaitHandle.WaitAll(); 
            end = DateTime.Now.Ticks;
            Console.WriteLine(" =" + Convert.ToString(end - start));
            Console.ReadLine();

        }
    }