提取网站上的超链接

try              {                  //抓取网页中的内容                   WebRequest request = WebRequest.Create(textBox2.Text.ToString());                  WebResponse response = request.GetResponse();                  StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("gb2312"));                  //textBox1.Text = reader.ReadToEnd();                     string text = reader.ReadToEnd();                  textBox1.Text = text;                  // string tt = Regex.Match(text, @"http://([/w-]+/.)+[/w-]+(/[/w- ./?%&=]*)?").ToString();                   char[] spstr = { '<','>'};                  //将字符串分隔成数组                   string[] str = text.Split(spstr ,10000);                  //定义字符串用来存储分隔后字符串                   string strtext = "";                  //用foreach遍历分隔后的字符串数组                   foreach (string i in str)                  {                      string str2;                      //用正则表达式匹配一个http超链接                       if((str2=Regex.Match(i, @"http://([/w-]+/.)+[/w-]+(/[/w- ./?%&=]*)?").ToString().Trim ()).Length !=0)                      {                          strtext += str2 + "/r/n";  //  /r/n表示TextBox中的换行符。一个/n不行                       }                  }                  textBox3.Text = strtext ;                  reader.Close();                  reader.Dispose();                  response.Close();              }              catch (Exception ex)              {                  MessageBox.Show(ex.Message);              }  try            {                //抓取网页中的内容                WebRequest request = WebRequest.Create(textBox2.Text.ToString());                WebResponse response = request.GetResponse();                StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("gb2312"));                //textBox1.Text = reader.ReadToEnd();
                string text = reader.ReadToEnd();                textBox1.Text = text;                // string tt = Regex.Match(text, @"http://([/w-]+/.)+[/w-]+(/[/w- ./?%&=]*)?").ToString();                char[] spstr = { '<','>'};                //将字符串分隔成数组                string[] str = text.Split(spstr ,10000);                //定义字符串用来存储分隔后字符串                string strtext = "";                //用foreach遍历分隔后的字符串数组                foreach (string i in str)                {                    string str2;                    //用正则表达式匹配一个http超链接                    if((str2=Regex.Match(i, @"http://([/w-]+/.)+[/w-]+(/[/w- ./?%&=]*)?").ToString().Trim ()).Length !=0)                    {                        strtext += str2 + "/r/n";  //  /r/n表示TextBox中的换行符。一个/n不行                    }                }                textBox3.Text = strtext ;                reader.Close();                reader.Dispose();                response.Close();            }            catch (Exception ex)            {                MessageBox.Show(ex.Message);            }