正则表达式抓取网页信息

//url 地址 

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("URL")); 

            HttpWebResponse response = (HttpWebResponse)request.GetResponse(); 

            //浏览器类型设置 

            request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; .NET CLR 3.5.21022; .NET CLR 1.0.3705; .NET CLR 1.1.4322)"; 

            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("UTF-8")); 

              //返回的html网页数据 

            String htmlStr = reader.ReadToEnd();

  /// <summary> 

        /// 获得颜色 

         /// </summary> 

        /// <param name="htmlStr"></param> 

        /// <returns></returns> 

        public String getColor(String htmlStr) 

        { 

  //获取class为  DetailsC_Sku的html ，还可改为ID的方式    

//string regstr6 = @"<(?<HtmlTag>[\w]+)[^>]*\s[iI][dD]=(?<Quote>";     

string regstr6 = @"<(?<HtmlTag>[\w]+)[^>]*\s[cC][lL][aA][sS][sS]=(?<Quote>"; 

            string regstr7 = "[\"']?)DetailsC_Sku(?(Quote)"; 

            string regstr8 = @"\k<Quote>)"; 

            string regstr9 = "[\"']?[^>]*>"; 

            string regstr10 = @"((?<Nested><\k<HtmlTag>[^>]*>)|</\k<HtmlTag>>(?<-Nested>)|.*?)*</\k<HtmlTag>>"; 

            StringBuilder sb2 = new StringBuilder(); 

            sb2.Append(regstr6); 

            sb2.Append(regstr7); 

            sb2.Append(regstr8); 

            sb2.Append(regstr9); 

            sb2.Append(regstr10); 

        //根据正则表达式获取的html 

            String sizeHtml = Regex.Match(htmlStr, sb2.ToString(), RegexOptions.Singleline).ToString(); 

            if (!String.IsNullOrEmpty(sizeHtml)) 

            { 

                String newhtml = htmlStr.Replace(sizeHtml, ""); 

                string regstr11 = @"<(?<HtmlTag>[\w]+)[^>]*\s[cC][lL][aA][sS][sS]=(?<Quote>"; 

                string regstr12 = "[\"']?)DetailsC_Sku(?(Quote)"; 

                string regstr13 = @"\k<Quote>)"; 

                string regstr14 = "[\"']?[^>]*>"; 

                string regstr15 = @"((?<Nested><\k<HtmlTag>[^>]*>)|</\k<HtmlTag>>(?<-Nested>)|.*?)*</\k<HtmlTag>>"; 

                StringBuilder sb3 = new StringBuilder(); 

                sb3.Append(regstr11); 

                sb3.Append(regstr12); 

                sb3.Append(regstr13); 

                sb3.Append(regstr14); 

                sb3.Append(regstr15); 

                String colorHtml = Regex.Match(newhtml, sb3.ToString(), RegexOptions.Singleline).ToString(); 

                if (String.IsNullOrEmpty(colorHtml)) 

                    return ""; 

                //找出此colorHtml中的所有a 标签 

                Regex regex2 = new Regex(@"<a.*?>[\s\S]*?<\/a>"); 

                MatchCollection mc2 = regex2.Matches(colorHtml); 

                StringBuilder sbs = new StringBuilder(); 

                //循环找到颜色 

                if (mc2.Count > 0) 

                { 

                    foreach (Match mm in mc2) 

                    { 

                        sbs.Append(RemoveHtml(mm.Value.ToString())).Append(","); 

                    } 

                } 

                return sbs.ToString(); 

            } 

            return ""; 

        }

/// <summary> 

      /// 替换字符串中的html标签为空返回标签里的内容 

       /// </summary> 

       /// <param name="src"></param> 

       /// <returns></returns> 

       public string RemoveHtml(string src) 

       { 

           Regex htmlReg = new Regex(@"<[^>]+>", RegexOptions.Compiled | RegexOptions.IgnoreCase); 

           Regex htmlSpaceReg = new Regex("\\&nbsp\\;", RegexOptions.Compiled | RegexOptions.IgnoreCase); 

           Regex spaceReg = new Regex("\\s{2,}|\\ \\;", RegexOptions.Compiled | RegexOptions.IgnoreCase); 

           Regex styleReg = new Regex(@"<style(.*?)</style>", RegexOptions.Compiled | RegexOptions.IgnoreCase); 

           Regex scriptReg = new Regex(@"<script(.*?)</script>", RegexOptions.Compiled | RegexOptions.IgnoreCase); 

           src = styleReg.Replace(src, string.Empty); 

           src = scriptReg.Replace(src, string.Empty); 

           src = htmlReg.Replace(src, string.Empty); 

           src = htmlSpaceReg.Replace(src, " "); 

           src = spaceReg.Replace(src, " "); 

           return src.Trim(); 

       }