System.IO.FileStream.EndRead C# (CSharp) Method

        public override int EndRead(IAsyncResult asyncResult)
        {
            if (asyncResult == null)
                throw new ArgumentNullException(nameof(asyncResult));

            if (!IsAsync)
                return base.EndRead(asyncResult);
            else
                return TaskToApm.End<int>(asyncResult);
        }

        static void Main(string[] args)
        {
            //AsyncReadOneFile();

            //AsyncReadMultiplyFiles();

            FileStream fs = new FileStream(@"../../Program.cs", FileMode.Open,
               FileAccess.Read, FileShare.Read, 1024,
               FileOptions.Asynchronous);

            Byte[] data = new Byte[100];

            IAsyncResult ar = fs.BeginRead(data, 0, data.Length, null, null);

            while (!ar.IsCompleted)
            {
                Console.WriteLine("Операция не завершена, ожидайте...");
                Thread.Sleep(10);
            }

            Int32 bytesRead = fs.EndRead(ar);

            fs.Close();

            Console.WriteLine("Количество считаных байт = {0}", bytesRead);
            Console.WriteLine(Encoding.UTF8.GetString(data).Remove(0, 1));
        }