采集网页内容的c#类，可以像火车头一样指定目标字符串前面的字符和后面的字符，自动截取到目标字符串，测试效果不错：

using System.IO;using System.Net;using System.Text;using System;using System.Text.RegularExpressions;using System.Collections.Generic;

namespace testtaobao {

    public class caiji

    {

        #region 获取网页内容

        /// <summary>

        /// 获取网页内容

        /// </summary>

        /// <param name="url">网址</param>

        /// <param name="code">网页编码例如GB2312</param>

        /// <returns>网页源码</returns>

        public string gethtml(string url,string code){

            string strResult;

            try

            {

                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

                //声明一个HttpWebRequest请求   

                request.Timeout = 30000;

                //设置连接超时时间   

                request.Headers.Set("Pragma", "no-cache");

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

                Stream streamReceive = response.GetResponseStream();

                Encoding encoding = Encoding.GetEncoding(code);

                StreamReader streamReader = new StreamReader(streamReceive, encoding);

                strResult = streamReader.ReadToEnd();

                return strResult;

            }

            catch (Exception ex)

            {

                throw ex;

            }

        }

        #endregion

        #region 替换换行符

        /// <summary>

        /// 替换掉网页源码里面的换行符，方便匹配

        /// </summary>

        /// <param name="HtmlCode">html代码</param>

        /// <returns>去除换行符后的字符串</returns>

        public string ReplaceEnter(string HtmlCode)

        {

            string s = "";

            if (HtmlCode == null || HtmlCode == "")

                s = "";

            else

                s = HtmlCode.Replace("\"", "");

            s = s.Replace("\r\n", "");

            return s;

        }

        #endregion

        #region 执行正则提取出值

        /// <summary>

        /// 执行正则提取出值

        /// </summary>

        /// <param name="RegexString">正则表达式</param>

        /// <param name="RemoteStr">HtmlCode源代码</param>

        /// <returns></returns>

        public MatchCollection GetRegValue(string RegexString, string RemoteStr)

        {

            Regex r = new Regex(RegexString,RegexOptions.Multiline);            

            MatchCollection matches = r.Matches(RemoteStr);

            return matches;

        }

        #endregion

        #region 获取目标字符串

        /// <summary>

        /// 获取目标字符串

        /// </summary>

        /// <param name="fstr">目标字符串前面的字串</param>

        /// <param name="estr">目标字符串后面的字串</param>

        /// <param name="scstr">源字符串</param>

        /// <returns>匹配到的字符串数组</returns>

        public List<string> getstr(string fstr, string estr, string scstr) {

            //StringBuilder stb = new StringBuilder();

            string regstr = fstr + @".*?" + estr;

            List<string> rlist = new List<string>();

            MatchCollection match = GetRegValue(regstr, scstr);

            for (int i = 0; i < match.Count; i++)

            {

                string tpstr = match[i].ToString();

                tpstr = tpstr.Replace(fstr, "");

                tpstr = tpstr.Replace(estr, "");

                rlist.Add(tpstr);

            }

            return rlist;

        }

        #endregion

    }

}

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