.Net截取指定长度的汉字,其余用...表示的方法

        /// <summary>
        /// 将指定字符串按指定长度进行剪切
        /// </summary>
        /// <param name="oldStr">需要截断的字符串</param>
        /// <param name="maxLength">字符串的最大长度</param>
        /// <param name="endWith">超过长度的后缀</param>
        /// <returns>如果超过长度,返回截断后的新字符加上后缀,否则返回原字符串</returns>
        public static string StringTruncat(string oldStr, int maxLength, string endWith)
        {
            if(string.IsNullOrEmpty(oldStr))
                //throw new NullReferenceException("原字符不能为空");
                return oldStr+endWith;
            if (maxLength < 1)
                throw new Exception("返回值长度必须大于[0]");
            if (oldStr.Length > maxLength) 
            {
                string strTmp = oldStr.Substring(0, maxLength);
                if (string.IsNullOrEmpty(endWith))
                    return strTmp;
                else
                    return strTmp + endWith;
            }
            return oldStr;
        }