/// <summary>         /// 转义字符串中所有正则特殊字符         /// </summary>         /// <param name="input">传入字符串</param>         /// <returns></returns>         string FilterString(string input)         {             input = input.Replace("\\", "\\\\");//先替换“\”，不然后面会因为替换出现其他的“\”             Regex r = new Regex("[\\*\\.\\?\\+\\$\\^\\[\\]\\(\\)\\{\\}\\|\\/]");             MatchCollection ms = r.Matches(input);             List<string> list = new List<string>();             foreach (Match item in ms)             {                 if (list.Contains(item.Value))                     continue;                 input = input.Replace(item.Value, "\\" + item.Value);                 list.Add(item.Value);             }             return input;         }