使用mongodb实现多选

下面为C#实现的各个进制互转等帮助类方法

        /// <summary>
        /// 二进制字符串转byte[]
        /// </summary>
        /// <param name="binaryStr"></param>
        /// <returns></returns>
        public static byte[] ConvertBinaryStringToBytes(string binaryStr)
        {
            binaryStr = binaryStr.Replace("-", string.Empty);
            binaryStr = BinaryLengthAppendTo8(binaryStr);
            byte[] resultantArray = new byte[binaryStr.Length / 8];            for (int i = 0; i < resultantArray.Length; i++)
            {
                var str = binaryStr.Substring(i * 8, 8);
                resultantArray[i] = Convert.ToByte(str, 2);
            }            return resultantArray;
        }        /// <summary>
        /// 二进制字符串转base64
        /// </summary>
        /// <param name="binaryStr"></param>
        /// <returns></returns>
        public static string ConvertBinaryStringToBase64(string binaryStr)
        {
            var byteArr = ConvertBinaryStringToByteArr(binaryStr);            return Convert.ToBase64String(byteArr);
        }        /// <summary>
        /// 10进制转二进制字符串("100010010"格式)
        /// </summary>
        /// <param name="num"></param>
        /// <returns></returns>
        public static string ConvertDoubleToString(double num)
        {
            List<string> binary = new List<string>();            while (num > 0)
            {                double tmp = num;
                num = Math.Floor(tmp / 2);
                binary.Add((tmp % 2).ToString());
            }
            binary.Reverse();            return string.Join(string.Empty, binary);
        }        /// <summary>
        /// btye[]转二进制字符串
        /// </summary>
        /// <param name="bindata"></param>
        /// <returns></returns>
        public static string ConvertBinaryToString(byte[] bindata)
        {
            StringBuilder sb = new StringBuilder();            for (int i = 0; i < bindata.Length; i++)
            {                string hv = Convert.ToString(bindata[i], 2);
                hv = BinaryLengthAppendTo8(hv);
                sb.Append(hv);
            }            return sb.ToString();
        }        public static byte[] ConvertDoubleToBytes(double num)
        {            return ConvertBinaryStringToByteArr(ConvertDoubleToString(num));
        }        /// <summary>
        /// 转换bindata到十进制double(强转溢出后返回-1)
        /// </summary>
        /// <param name="bindata"></param>
        /// <returns></returns>
        public static double ConvertBinaryToDouble(byte[] bindata)
        {            string binary = ConvertBinaryToString(bindata);            return ConvertBinaryStrToDouble(binary);

        }        /// <summary>
        /// 转换"10101010"到十进制double(强转溢出后返回-1)
        /// </summary>
        /// <param name="binaryStr"></param>
        /// <returns></returns>
        public static double ConvertBinaryStrToDouble(string binaryStr)
        {            try
            {                int binLen = binaryStr.Length;                double sum = 0;                for (int i = 0; i < binLen; i++)
                {                    if (binaryStr[i] == '1')
                    {
                        sum += Math.Pow(2, binLen - i - 1);
                    }
                }                if (double.IsInfinity(sum))
                {                    throw new Exception("溢出");
                }                return sum;
            }            catch
            {                return -1;
            }

        }        private static string BinaryLengthAppendTo8(string binaryStr)
        {            int m = binaryStr.Length % 8;            if (m != 0)
            {
                StringBuilder sb = new StringBuilder();                for (int i = 0; i < 8 - m; i++)
                {
                    sb.Append("0");
                }
                binaryStr = sb.ToString() + binaryStr;
            }            return binaryStr;
        }

作者：太白菜Rennbon
链接：https://www.jianshu.com/p/5bb02d0641e8