C# 正则提取网页内容

        string zhengze = "(?<=<title>)(.*?)(?=</title>)"; //建立正则匹配
        try
        {

            Match m = Regex.Match(result, zhengze);  //正则匹配
            if (m.Success)
            {
                HtmlCodeNew = m.Value;
                Response.Write(HtmlCodeNew);
            }
        }
        catch
        {
            
        }