字符串替换和高亮关键词的算法

2014-11-12 17:42:37 访问(2464) 赞(0) 踩(0)

通过字符串逐个比较和替换实现，没有用正则表达式，效率可能有点不好，但能简单实现要求：


    /// <summary>
    /// 关键词匹配的Class
    /// </summary>
    [Serializable]
    public class KeyWordTextClass
    {

        /// <summary>
        /// 关键词匹配的Class
        /// </summary>
        /// <param name="_IsKeyWord"></param>
        /// <param name="_Text"></param>
        public KeyWordTextClass(bool _IsKeyWord, string _Text)
        {
            m_IsKeyWord = _IsKeyWord;

            m_Text = _Text;
        }

        /// <summary>
        /// 内容
        /// </summary>
        protected string m_Text = "";

        /// <summary>
        /// 内容
        /// </summary>
        public string Text
        {
            get
            {
                return m_Text;
            }
        }

        /// <summary>
        /// 是否关键字
        /// </summary>
        protected bool m_IsKeyWord = false;

        /// <summary>
        /// 是否关键字
        /// </summary>
        public bool IsKeyWord
        {
            get
            {
                return m_IsKeyWord;
            }
        }

        /// <summary>
        /// 将字符串分割成列表数组
        /// </summary>
        /// <param name="TheName"></param>
        /// <param name="KeyWord"></param>
        /// <returns></returns>
        public static List<KeyWordTextClass> BuildList
            (
                string TheName,
                string KeyWord
            )
        {
            if (TheName == null || TheName.Length == 0)
                return null;

            List<KeyWordTextClass> theResult = null;

            if (KeyWord == null || KeyWord.Length == 0 || KeyWord.Trim().Length == 0)
            {
                theResult = new List<KeyWordTextClass>();
                theResult.Add(new KeyWordTextClass(false, TheName));
                return theResult;
            }

            string[] sArray = KeyWord.Split(new char[] { ' ' });

            if (sArray == null || sArray.Length == 0)
            {
                theResult = new List<KeyWordTextClass>();
                theResult.Add(new KeyWordTextClass(false, TheName));
                return theResult;
            }

            int iLen = sArray.Length;

            if (iLen == 1)
            {
                string strKeyWord = sArray[0];

                if (strKeyWord == null)
                {
                    theResult = new List<KeyWordTextClass>();
                    theResult.Add(new KeyWordTextClass(false, TheName));
                    return theResult;
                }

                strKeyWord = strKeyWord.Trim();

                if (strKeyWord.Length == 0)
                {
                    theResult = new List<KeyWordTextClass>();
                    theResult.Add(new KeyWordTextClass(false, TheName));
                    return theResult;
                }

                int idx = -1;
                string lowerKeyWord = strKeyWord.ToLower();
                string strTheName = TheName;
                string lowerTheName = TheName.ToLower();
                int keyWordLen = strKeyWord.Length;
                theResult = new List<KeyWordTextClass>();

                while (true)
                {
                    idx = lowerTheName.IndexOf(lowerKeyWord);

                    if (idx == -1)
                    {
                        theResult.Add(new KeyWordTextClass(false, strTheName));
                        break;
                    }

                    if (idx != 0)
                    {
                        theResult.Add(new KeyWordTextClass(false, strTheName.Substring(0, idx)));
                    }

                    theResult.Add(new KeyWordTextClass(true, strTheName.Substring(idx, keyWordLen)));

                    strTheName = strTheName.Substring(idx + keyWordLen);
                    lowerTheName = lowerTheName.Substring(idx + keyWordLen);
                }

                return theResult;
            }
            else
            {
                bool isFirst = true;
                List<KeyWordTextClass> resultList = null;
                List<KeyWordTextClass> tmpList = null;

                foreach (string s in sArray)
                {
                    if (s == null || s.Trim().Length == 0)
                        continue;

                    if (isFirst)
                    {
                        theResult = BuildList(TheName, s);
                        isFirst = false;
                    }
                    else
                    {
                        resultList = new List<KeyWordTextClass>();

                        foreach (KeyWordTextClass ktc in theResult)
                        {
                            if (ktc == null)
                                continue;

                            if (ktc.IsKeyWord)
                            {
                                resultList.Add(ktc);
                                continue;
                            }

                            if (ktc.Text == null || ktc.Text.Length == 0)
                                continue;

                            tmpList = BuildList(ktc.Text, s);

                            if (tmpList != null)
                            {
                                foreach (KeyWordTextClass k in tmpList)
                                {
                                    if (k == null)
                                        continue;

                                    resultList.Add(k);
                                }
                            }
                        }

                        theResult = resultList;
                    }

                }
            }

            return theResult;

        }

        /// <summary>
        /// 重组字符串，实现对关键词高亮
        /// </summary>
        /// <param name="theList"></param>
        /// <param name="strColor"></param>
        /// <returns></returns>
        public static string BuildColorText(List<KeyWordTextClass> theList, string strColor)
        {
            if (theList == null || theList.Count == 0)
                return "";

            StringBuilder theResult = new StringBuilder();

            if(strColor == null || strColor.Length == 0)
                throw new Exception("strColor == null || strColor.Length == 0");

            strColor = strColor.Replace("\"", "&quot;");

            foreach (KeyWordTextClass ktc in theList)
            {
                if (ktc == null)
                    continue;

                if (ktc.Text == null || ktc.Text.Length == 0)
                    continue;

                if (ktc.IsKeyWord)
                {
                    theResult.Append("<font color=\"" + strColor + "\">" + ktc.Text + "</font>");
                }
                else
                {
                    theResult.Append(ktc.Text);
                }
            }

            return theResult.ToString();

        }

        /// <summary>
        /// 实现字符串替换和高亮关键词 
        /// </summary>
        /// <param name="TheName"></param>
        /// <param name="KeyWord"></param>
        /// <param name="strColor"></param>
        /// <returns></returns>
        public static string ToColorText
            (
                string TheName,
                string KeyWord, 
                string strColor
            )
        {
            List<KeyWordTextClass> theList = BuildList(TheName, KeyWord);

            return BuildColorText(theList, strColor);
        }
    }