using System;
using System.Collections;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using System.Threading;
using System.Windows.Forms;

namespace Traning
{
    [Serializable]
    class MyArr : IEnumerable
    {
        private int[] arr;

        public int Size{ get => arr.Length;}

        public MyArr(int size = 0) { arr = new int[size]; }
        public MyArr(int[] _arr) => arr = _arr;

        public MyArr FullRandomNumres()
        {
            var rnd = new Random();
            for (int i = 0; i < arr.Length; ++i) arr[i] = rnd.Next(-100, 100);
            return this;
        }

        public MyArr Print()
        {
            foreach (var n in arr) Console.Write($"{n}  ");
            return this;
        }

        public static void SaveToFile(string filename, MyArr value)
        {
            using (var fs = new FileStream(filename, FileMode.OpenOrCreate))
            {
                new BinaryFormatter().Serialize(fs,value);
            }
        }

        public static MyArr LoadFromFile(string filename)
        {
            using (var fs = File.OpenRead(filename))
            {
                return new MyArr( new BinaryFormatter().Deserialize(fs) as int []);
            }
        }

        public int this[int index] { get => arr[index]; set => arr[index] = value;}

        public IEnumerator GetEnumerator() => arr.GetEnumerator();
    }

    public delegate int DisplayHandler();
    public delegate DialogResult show(string x);

    class Program
    {
       static void Main(string[] args)
        {
            /*var arr = new MyArr(10);
            arr.FullRandomNumres().Print();
            Console.WriteLine();

            var filename = @"c:\input";

            MyArr.SaveToFile(filename, arr);
            arr = MyArr.LoadFromFile(filename);
            arr.Print();*/
            DisplayHandler handler = new DisplayHandler(Display);
            var s = new show((x) => MessageBox.Show(x));

            IAsyncResult resultObj = handler.BeginInvoke(null, null);
            var rs = s.BeginInvoke("Hello",null, null);

            Thread.Sleep(1000);

            Console.WriteLine("Продолжается работа метода Main");
            int result = handler.EndInvoke(resultObj);

            Console.WriteLine("Результат равен {0}", result);

        }
        static int Display()
        {
            Console.WriteLine("Начинается работа метода Display...");

            int result = 0;
            for (int i = 1; i < 10; i++)
            {
                result += i * i;
            }
            Thread.Sleep(3000);
            Console.WriteLine("Завершается работа метода Display....");
            return result;
        }
    }
}