天天看點

C#資料采集用到的幾個方法

這兩天在做資料采集,是以整理了下資料采集要用到的一些方法。因為我采集的資料比較簡單,是以沒有用到架構。比較有名的兩個架構 HtmlAgilityPack 和 Jumony,感興趣的可以研究下。當然,火車頭采集工具也很友善,不過要付費。下面是整理的代碼:

   /// <summary>
    /// Html正則處理幫助類
    /// </summary>
    public class HtmlRegex
    {
        /// <summary>
        /// 比對所有Html标簽
        /// </summary>
        const string HTMLALLTAG = @"<[^>]+>|</[^>]+>";

        /// <summary>
        /// 删除所有html标簽
        /// </summary>
        /// <param name="content">原HTML代碼</param>
        /// <returns></returns>
        public static string RemoveAllHtml(string content)
        {
            return Regex.Replace(content, HTMLALLTAG, "");
        }

        /// <summary>
        /// 根據正則比對擷取指定内容
        /// </summary>
        /// <param name="regStr">正則</param>
        /// <param name="content">原HTML代碼</param>
        /// <param name="hashtml">是否包含HTML标簽</param>
        /// <returns></returns>
        public static string GetStrByRegex(string regStr, string content, bool hashtml = true)
        {
            string result = string.Empty;
            Regex reg = new Regex(regStr);
            Match mth = reg.Match(content);

            if (mth.Success)
            {
                result = mth.Value;
                if (!hashtml) result = HtmlRegex.RemoveAllHtml(result); //去除html标簽

            }
            return result;
        }

        /// <summary>
        /// 擷取指定位置的html代碼
        /// </summary>
        /// <param name="start">起始字元串</param>
        /// <param name="end">結束字元串</param>
        /// <param name="content">原HTML代碼</param>
        /// <param name="hasHtml">是否包含HTML标簽</param>
        /// <returns></returns>
        public static string GetStrByRegex(string start, string end, string content, bool hasHtml = true)
        {
            string result = string.Empty;
            string regStr = @"(?is)(" + start + ").*?(" + end + ")";
            Regex reg = new Regex(regStr);
            Match mth = reg.Match(content);
            if (mth.Success)
            {
                result = mth.Value;
                if (!hasHtml) result = HtmlRegex.RemoveAllHtml(result); //去除html标簽
            }
            return result;
        }

        /// <summary>
        /// 擷取比對的字元串清單
        /// </summary>
        /// <param name="regStr">正則</param>
        /// <param name="content">原HTML代碼</param>
        /// <returns></returns>
        public static List<string> GetStrListByRegex(string regStr, string content)
        {
            List<string> strList = null;
            MatchCollection mc = null;
            try
            {
                Regex reg = new Regex(regStr);
                mc = reg.Matches(content);
                if (mc.Count > 0)
                {
                    strList = new List<string>();
                    for (int i = 0; i < mc.Count; i++)
                    {
                        strList.Add(mc[i].Value);
                    }
                }
            }
            catch
            {
                strList = null;
            }
            return strList;
        }

        /// <summary>
        /// 擷取比對的字元串清單
        /// </summary>
        /// <param name="start">起始字元串</param>
        /// <param name="end">結束字元串</param>
        /// <param name="content">原HTML代碼</param>
        /// <returns></returns>
        public static List<string> GetStrListByRegex(string start, string end, string content)
        {
            List<string> strList = null;
            MatchCollection mc = null;
            string regStr = @"(?is)(" + start + ").*?(" + end + ")";
            try
            {
                Regex reg = new Regex(regStr);
                mc = reg.Matches(content);
                if (mc.Count > 0)
                {
                    strList = new List<string>();
                    for (int i = 0; i < mc.Count; i++)
                    {
                        strList.Add(mc[i].Value);
                    }
                }
            }
            catch
            {
                strList = null;
            }
            return strList;
        }

    }