.net IAsyncResult 异步操作

        //定义一个委托
        public delegate int DoSomething(int count);

        //BeginInvoke 的回调函数
        private static void Execute(IAsyncResult async)
        {
            DoSomething temp = (DoSomething)async.AsyncState;
            int sum = temp.EndInvoke(async);
            Console.WriteLine("线程结束：值为" + sum);
        }

   

        /// <summary>
        /// 判断输入的整数是不是素数
        /// </summary>
        /// <param name="candidate">输入的整数</param>
        /// <returns>为素数返回true,否则返回false</returns>
        public static bool IsPrime(int candidate)
        {
            bool retVal = true; 
            //使用递增方式会更有效率，
            //但是在演示取消功能时，使用递减的数字会更好。
            //for (int i = 2; i < candidate / 2; i++)
            for (int i = candidate / 2 + 1; i > 1; i--)
            {
                if (candidate % i == 0)
                {
                    retVal = false;
                    break;
                }
            }
            return retVal;
        }
 
        private static int maseggs(int count)
        {
            int result = 0;
            for (int index = 0; index < count; index++)
            {
                if (IsPrime(index + 1))
                {
                    result++;
                }
            }
            return result;
        }

      static void Main(string[] args)
        {
            DoSomething hidands = new DoSomething(maseggs);
            IAsyncResult async = hidands.BeginInvoke(100000, new AsyncCallback(Execute), hidands);
            //这里还有100行代码         
            Console.WriteLine("消息获取成功");
 

            Console.ReadLine();
        }