C#异步编程

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
namespace ConsoleApplication1
{
    class Program
    {
        private static int Task(int ms)
        {
            Console.WriteLine("任务开始");
            Thread.Sleep(ms);
            Random random = new Random();
            int n = random.Next(10000);
            Console.WriteLine("任务完成");
            return n;
        }
        private delegate int NewTaskDelegate(int ms);
        static void Main(string[] args)
        {
            NewTaskDelegate task = Task;
            IAsyncResult asyncResult = task.BeginInvoke(2000, null, null);  //第一个参数传递给调用方法
            //EndInvoke方法将被阻隔2秒
            /*while (!asyncResult.AsyncWaitHandle.WaitOne(100, false))
            {
                Console.Write("*");
            }*/
            //EndInvoke方法将被阻隔2秒
            while (!asyncResult.IsCompleted)
            {
                Console.Write("*");
                Thread.Sleep(100);
            }
            int result = task.EndInvoke(asyncResult);
            Console.WriteLine(result);
        }
    }
}