System.BitConverter.GetHexValue C# (CSharp) Метод

        private static char GetHexValue(int i) {
            BCLDebug.Assert( i >=0 && i <16, "i is out of range.");
            if (i<10) {
                return (char)(i + '0');
            }
    
            return (char)(i - 10 + 'A');
        }

        public static string ToString(byte[] value, int startIndex, int length)
        {
            if (value == null)
            {
                throw new ArgumentNullException("value");
            }
            if (startIndex < 0 || (startIndex >= value.Length && startIndex > 0))
            {
                throw new ArgumentOutOfRangeException("startIndex", Environment.GetResourceString("ArgumentOutOfRange_StartIndex"));
            }
            if (length < 0)
            {
                throw new ArgumentOutOfRangeException("length", Environment.GetResourceString("ArgumentOutOfRange_GenericPositive"));
            }
            if (startIndex > value.Length - length)
            {
                throw new ArgumentException(Environment.GetResourceString("Arg_ArrayPlusOffTooSmall"));
            }
            if (length == 0)
            {
                return(string.Empty);
            }
            if (length > 715827882)
            {
                throw new ArgumentOutOfRangeException("length", Environment.GetResourceString("ArgumentOutOfRange_LengthTooLarge", new object[]
                {
                    715827882
                }));
            }
            int num = length * 3;

            char[] array = new char[num];
            int    num2  = startIndex;

            for (int i = 0; i < num; i += 3)
            {
                byte b = value[num2++];
                array[i]     = BitConverter.GetHexValue((int)(b / 16));
                array[i + 1] = BitConverter.GetHexValue((int)(b % 16));
                array[i + 2] = '-';
            }
            return(new string(array, 0, array.Length - 1));
        }