C#10进制与34进制的互转

private string repString = "0123456789ABCDEFGHJKLMNPQRSTUVWXYZ";（已排除字母I和O）

//10进制转34进制

private string  _10To34_(int Num)
        {
            return repString.Substring(Num / (34 * 34 * 34),1) + repString.Substring(Num / (34 * 34) % 34,1) + repString.Substring(Num / 34 % 34,1) + repString.Substring(Num % 34,1);
        }

//34进制转10进制

private int _34To10_(string Numstring)
        {
            return repString.IndexOf(Numstring.Substring(3, 1)) + 34 * (repString.IndexOf(Numstring.Substring(2, 1))) + 34 * 34 * (repString.IndexOf(Numstring.Substring(1, 1))) + 34 * 34 * 34 * (repString.IndexOf(Numstring.Substring(0, 1)));
          }