using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

namespace System.Web.Mvc //修改为所属System.Web.Mvc命名空间 方便直接使用

{

    /// <summary>

    /// 截取字符串类

    /// </summary>

    public static class CutOfTextExtersions

    {

        /// <summary>

        /// 截取字符串方法

        /// </summary>

        /// <param name="helper"></param>

        /// <param name="str">字符串</param>

        /// <param name="len">长度</param>

        /// <param name="flag">是否显示。。。</param>

        /// <returns></returns>

        public static string GotTopic(this HtmlHelper helper, string str, int len, bool flag)

        {

            if (str != null && str != "")

            {

                string clearstr = str.RemoveHTML();

                int count = ;

                string strTemp = "";

                for (int i = ; i < clearstr.Length; i++)

                {

                    if (Math.Abs(((int)(clearstr.Substring(i, ).ToCharArray())[])) > )

                        count += ;

                    else

                        count += ;

                    if (count <= len)

                        strTemp += clearstr.Substring(i, );

                    else

                    {

                        strTemp = strTemp + (flag == true ? "…" : "");

                        return str.Replace(clearstr, strTemp);

                    }

                }

                return str.Replace(clearstr, strTemp).Replace("　", "").Trim();

            }

            else

                return "";

        }

        public static string RemoveHTML(this string str)

        {

            try

            {

                if (str != "")

                {

                    str = System.Text.RegularExpressions.Regex.Replace(str, "<[^>]*>", "");

                    str = str.Replace("&nbsp;", " ");

                    return str;

                }

                else

                    return "";

            }

            catch

            {

                return "";

            }

        }

    }

}