using System;  using System.Collections.Generic;  using System.IO;  using System.Linq;  using System.Net;  using System.Text;  using System.Text.RegularExpressions;  using System.Threading.Tasks;    namespace _2015._5._23通过WebClient类发起请求并下载html  {      class Program      {          static void Main(string[] args)          {              #region 抓取网页邮箱              //string url = "http://zhidao.baidu.com/link?url=cvF0de2o9gkmk3zW2jY23TLEUs6wX-79E1DQVZG7qaBhEVT_xlh6TO7p0W4qwuAZ_InLymC_-mJBBcpdbzTeq_";              //WebClient wc = new WebClient();              //wc.Encoding = Encoding.UTF8;              //string str = wc.DownloadString(url);              //MatchCollection matchs=  Regex.Matches(str,@"\w+@([-\w])+([\.\w])+",RegexOptions.ECMAScript);              //foreach (Match item in matchs)              //{              //    Console.WriteLine(item.Value);              //}              //Console.WriteLine(matchs.Count);              #endregion                #region 抓取网页图片                //WebClient wc = new WebClient();              //wc.Encoding = Encoding.UTF8;              下载源网页代码              //string html = wc.DownloadString("http://dongxi.douban.com/?dcs=top-nav&dcm=douban");              //MatchCollection matches= Regex.Matches(html,"
     
      ");              //foreach (Match item in matches)              //{              //    //下载图片到指定路径              //    wc.DownloadFile(item.Groups[1].Value,@"c:\mv\"+Path.GetFileName(item.Groups[1].Value));              //}              //Console.WriteLine(matches.Count);               #endregion 爬一些信息                WebClient wc = new WebClient();              wc.Encoding = Encoding.UTF8;              string html = wc.DownloadString("http://www.lagou.com/");                MatchCollection matches= Regex.Matches(html,"
      
       (.*)");              foreach (Match item in matches)              {                  Console.WriteLine(item.Groups[1].Value);              }              Console.WriteLine(matches.Count);              Console.ReadKey();                                            }      }  }