简单的搜索高亮类

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;

namespace siteadmin
{
    public class search
    {
        public enum enStyle : int
        {
            red = 1,
            black = 2,
            yellow = 3,
            white = 4,
            blue = 5,
            green = 6,
            other = -1
        }


        private static string[] colorStr = new string[] { "red", "black", "yellow", "white", "blue", "green" };

        public static string otherBKColor;
        public static string OtherBKColor
        {
            set { otherBKColor = value; }
        }

        public static string otherPenColor;
        public static string OtherPenColor
        {
            set { otherPenColor = value; }
        }
        /// <summary>
        /// 高亮搜索内容高亮显示类
        /// </summary>
        /// <param name="content">内容</param>
        /// <param name="key">搜索键</param>
        /// <param name="maxLenght">string最大长度,-1为关闭</param>
        /// <param name="colorStyle">样式</param>
        /// <param name="endString">结尾字符</param>
        /// <returns></returns>
        public static string highLightStr(string content, string key, int maxLenght, enStyle BKcolorStyle, enStyle penColorStyle, string endString)
        {
            if (content.Length <= 0 || key.Length <= 0)
            {
                return content;
            }


            string staSpan = null;
            if ((int)BKcolorStyle == -1)
            {
                staSpan = "<span style='background-color:" + otherBKColor + ";color:" + otherPenColor + "'>";
            }
            else
            {
                staSpan = "<span style='background-color:" + colorStr[(int)BKcolorStyle - 1] + ";color:" + colorStr[(int)penColorStyle - 1] + "'>";

            }
            string endSpan = "</span>";


            int temp = System.Globalization.CultureInfo.InvariantCulture.CompareInfo.IndexOf(content, key, System.Globalization.CompareOptions.IgnoreCase);

            if (temp >= 0)
            {
                if (maxLenght != -1)
                {

                    if(content.Length>maxLenght)
                    { 
                        //1.如果关键字前面有maxLenght/2的字符串
                        if (temp > maxLenght / 2)
                        { 
                            //获取截取开头位置索引
                            int staIndex=temp-(maxLenght/2);
                            //开头索引足够截取到maxLength个字符串
                            if(content.Length-staIndex>maxLenght)
                            {
                                content=content.Substring(staIndex,maxLenght);
                            }
                            //后面的不够截取
                            else
                            {
                             //需要往前移动的位数
                                int i=maxLenght-(content.Length-staIndex);   
                             //往前移动
                                staIndex=staIndex-i;
                                content=content.Substring(staIndex,maxLenght);
                            }
                        }
                    
                        else
                        {
                            content=content.Substring(0,maxLenght);
                        }
                    }
                    



                }
                temp = System.Globalization.CultureInfo.InvariantCulture.CompareInfo.IndexOf(content, key, System.Globalization.CompareOptions.IgnoreCase);
                content = content.Insert(temp, staSpan);
                content = content.Insert(staSpan.Length + temp + key.Length, endSpan);

            }


            return content + endString;

        }


    }
}