从页面中取出email地址和相对链接及绝对链接的代码...

private string FetchPage(String url) //取页面指定URL页面的源码
 {
  String page = "null";
 try
 {
  WebClient mywc = new WebClient();
  using(Stream strm = mywc.OpenRead(url))
 {
  StreamReader sr = new StreamReader(strm);
  page = sr.ReadToEnd();
  strm.Close();
 }
 }
 catch{}
 return page;
 }

  public string GetLink(String url) //绝对链接的
  {
   String content = this.FetchPage(url);
   //Regex linkRegex=new Regex("href\\s*=\\s*(?:\"(?<1>[^\"]*)\"|(?<1>\\S+)", RegexOptions.IgnoreCase);
   //@"^\w+((-\w+)|(\.\w+))*\@\w+((\.|-)\w+)*\.\w+$";
   Regex link=new Regex(@"http://([\w-]+\.)+[\w-]+(/[\w-./?%&=]*)?",RegexOptions.IgnoreCase);
   StringBuilder sb = new StringBuilder();
   MatchCollection emailmatchs = link.Matches(content);
   foreach(Match n in emailmatchs)
   {
    sb.Append(n.ToString());
    sb.Append(";");
   }
   if( sb.Length == 0 )
   {
    sb.Append("null");
   }
   return sb.ToString();
  }

public string GetEmailAddr(String url) //相对链接的
  {
   String content = this.FetchPage(url);
   //Regex linkRegex=new Regex("href\\s*=\\s*(?:\"(?<1>[^\"]*)\"|(?<1>\\S+)", RegexOptions.IgnoreCase);
   //@"^\w+((-\w+)|(\.\w+))*\@\w+((\.|-)\w+)*\.\w+$";
   Regex r=new Regex(@"\w+((-\w+)|(\.\w))*\@\w+((\.|-)\w+)*\.\w+[com|cn|com.cn|net|org|cc|uk]{1,6}",RegexOptions.IgnoreCase);
   StringBuilder sb = new StringBuilder();
   MatchCollection emailmatchs = r.Matches(content);
   foreach(Match n in emailmatchs)
   {
    sb.Append(n.ToString());
    sb.Append(";");
   }
   if( sb.Length == 0 )
    sb.Append("null");
   return sb.ToString();
  }