求助

  try
                        {
                       
                            string pageUrl = "" + sdr["58域名"] + "ershouche/pn" + i + "/";
                            string PageHtml = "";
                            string str = "";
                            richTextBox1.AppendText("开始抓取第" + i + "页数据....\r\n" + pageUrl + "\r\n");
                            richTextBox1.ScrollToCaret();
                            richTextBox1.Focus();
                            PageHtml = tools.HtmlPageStr(pageUrl, "utf-8").Replace("\"", "'").Replace("\r", "").Replace("\n", "").Replace("' >", "'>");
                            str = Regex.Match(PageHtml, "<!-- =E filterbar -->(.*?)<!-- =E tbimg/tbtxt -->").ToString();
                            foreach (Match match in Regex.Matches(str, "<td class='img'><a href='(.*?)' target='_blank'>"))
                            {
                                if (match.ToString().IndexOf("jump") == -1)
                                {
                                    string url = match.ToString().Replace("<td class='img'><a href='", "").Replace("' target='_blank'>", "");
                                    string BianHao = url.Substring(url.LastIndexOf("/") + 1).Replace(".shtml", "");
                                    if (Convert.ToInt32(SqlHelper.ExecuteScalar("select count(*) from 扒车编号 where 扒车位置='11' and 扒车编号='" + BianHao + "'").ToString()) <= 0)
                                    {
                                        richTextBox1.AppendText(url + "\r\n");                                        richTextBox1.ScrollToCaret();
                                        richTextBox1.Focus();
                                        bache(url, sdr["名称"].ToString(), BianHao);
                                        //int time = R.Next(1, 5);
                                        //richTextBox1.Text += "休息" + time + "秒钟....\r\n";
                                        //System.Threading.Thread.Sleep(time * 1000);//休息5秒钟
                                    }
                                }
                            }
                        }
                        catch (Exception e)
                        {
                        }