private static string GetTitle(string html)
        {
            string titleFilter = @"";
            string h1Filter = @".*?";
            string clearFilter = @"<.*?>";
            string title = "";
            Match match = Regex.Match(html, titleFilter, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                title = Regex.Replace(match.Groups[0].Value, clearFilter, "");
            }
            //获取h1标题 
            match = Regex.Match(html, h1Filter, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                string h1 = Regex.Replace(match.Groups[0].Value, clearFilter, "");
                if (!String.IsNullOrEmpty(h1) && title.StartsWith(h1))
                {
                    title = h1;
                }
            }
            return title;
        }