貌似比较难写，我也坐沙发等答案，呵呵

        /// <summary>
        /// 将指定的字符截取指定的长度
        /// </summary>
        /// <param name="s">要截取的字符串.</param>
        /// <param name="length">要截取的长度.</param>
        /// <param name="filterHtml">是否过滤html标签.</param>
        /// <param name="endWithPoints">是否以省略号结尾.</param>
        /// <param name="trim">是否去除左右两端的空白字符(过滤完html标签之后)</param>
        /// <returns>string.</returns>
        public static string BreakString(string s, int length, bool filterHtml, bool endWithPoints, bool trim) {
            if (string.IsNullOrEmpty(s)) {
                return s;
            }
            if (filterHtml) {
                s = Regex.Replace(s, @"<\/*[^<>]*>", "");
            }
            if (trim) {
                s = s.Trim();
            }
            StringBuilder result = new StringBuilder();
            for (int x = 0, len = 0; x < s.Length; x++) {
                if (Convert.ToInt32(Convert.ToChar(s.Substring(x, 1))) > 255) {
                    len += 2;
                }
                else {
                    len++;
                }
                if (len > length) {
                    if (endWithPoints) {
                        result.Append("...");
                    }
                    break;
                }
                result.Append(s.Substring(x, 1));
            }
            return result.ToString();
        }

遇到过，碰到那种图片性的文章更麻烦，一直没解决

楼主，你解决了要把方案贴出来呀。。