事件异步(EAP)使用事件异步处理一些耗时操作

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


namespace Demo
{
    class Program
    {

        static void Main(string[] args)
        {
            System.Net.WebClient client = new System.Net.WebClient();
            client.DownloadStringCompleted += new System.Net.DownloadStringCompletedEventHandler(client_DownloadStringCompleted);  //在异步资源下载操作完成时发生。
            client.DownloadStringAsync(new Uri("https://www.baidu.com"));  //异步下载地址

            for (int i = 0; i < 10;i++ )
            {
                Console.WriteLine("异步操作是执行此代码:"+i);
            }

            Console.ReadKey();
        }

        public static void client_DownloadStringCompleted(object sender, System.Net.DownloadStringCompletedEventArgs e)
        {
            System.Net.WebClient client = sender as System.Net.WebClient;
            Console.WriteLine(e.Result);  //异步处理的结果
        }

    }
}