C#_取随机字符

1.多位数字字母组成,每位取值0-9A-Z

     /// <summary>
     /// 获取下一个顺序码根据上一个(数字字母组合)
     /// </summary>
     /// <param name="str">上一个顺序码</param>
     /// <returns></returns>
     public static string ESequenceCode(string code)
     {
         if (string.IsNullOrWhiteSpace(code))
         {
             return "";
         }
         code = code.ToUpper();
         int max = ; int min = ;
         //数组48-57英文65-90(大写)/97-122(小写)
         char[] strs = code.ToCharArray();
         ASCIIEncoding ascii = new ASCIIEncoding();
         for (int i = strs.Length - ; i > -; i--)
         {
             int ascII = ascii.GetBytes(strs[i].ToString())[];
             int ascIINew = (ascII == max ? min : (ascII + (ascII ==  ?  : )));
             byte[] byteArray = new byte[] { (byte)ascIINew };
             strs[i] = Convert.ToChar(ascii.GetString(byteArray));
             if (ascII != max)
             {
                 break;
             }
         }
         return string.Join("", strs);
     }