Bio.IO.BAM.BAMFormatter.GetOptioanField C# (CSharp) Method

        private static byte[] GetOptioanField(SAMOptionalField field)
        {
            int valueSize = GetOptionalFieldValueSize(field);
            if (valueSize == 0)
            {
                string message = string.Format(CultureInfo.InvariantCulture, Properties.Resource.BAM_InvalidIntValueInOptField, field.Value, field.Tag);
                throw new FormatException(message);
            }

            int arrayLen = valueSize < 0 ? -valueSize : valueSize;
            arrayLen += 3;
            byte[] array = new byte[arrayLen];
            array[0] = (byte)field.Tag[0];
            array[1] = (byte)field.Tag[1];
            array[2] = (byte)field.VType[0];
            byte[] temparray = new byte[4];

            switch (field.VType)
            {
                case "A":  //  Printable character
                    array[3] = (byte)field.Value[0];
                    break;
                case "c": //signed 8-bit integer
                case "C": //unsigned 8-bit integer
                case "s": // signed 16 bit integer
                case "S"://unsinged 16 bit integer
                case "i": // signed 32 bit integer
                case "I": // unsigned 32 bit integer
                    if (valueSize == 1)
                    {
                        array[2] = (byte)'C';
                        array[3] = byte.Parse(field.Value, CultureInfo.InvariantCulture);
                    }
                    else if (valueSize == -1)
                    {
                        sbyte sb = sbyte.Parse(field.Value, CultureInfo.InvariantCulture);
                        array[2] = (byte)'c';
                        array[3] = (byte)sb;
                    }
                    else if (valueSize == 2)
                    {
                        UInt16 uint16value = UInt16.Parse(field.Value, CultureInfo.InvariantCulture);
                        temparray = Helper.GetLittleEndianByteArray(uint16value);
                        array[2] = (byte)'S';
                        array[3] = temparray[0];
                        array[4] = temparray[1];
                    }
                    else if (valueSize == -2)
                    {
                        Int16 int16value = Int16.Parse(field.Value, CultureInfo.InvariantCulture);
                        temparray = Helper.GetLittleEndianByteArray(int16value);
                        array[2] = (byte)'s';
                        array[3] = temparray[0];
                        array[4] = temparray[1];
                    }
                    else if (valueSize == 4)
                    {
                        uint uint32value = uint.Parse(field.Value, CultureInfo.InvariantCulture);
                        temparray = Helper.GetLittleEndianByteArray(uint32value);
                        array[2] = (byte)'I';
                        array[3] = temparray[0];
                        array[4] = temparray[1];
                        array[5] = temparray[2];
                        array[6] = temparray[3];
                    }
                    else
                    {
                        int int32value = int.Parse(field.Value, CultureInfo.InvariantCulture);
                        temparray = Helper.GetLittleEndianByteArray(int32value);
                        array[2] = (byte)'i';
                        array[3] = temparray[0];
                        array[4] = temparray[1];
                        array[5] = temparray[2];
                        array[6] = temparray[3];
                    }

                    break;
                case "f": // float
                    float floatvalue = float.Parse(field.Value, CultureInfo.InvariantCulture);
                    temparray = Helper.GetLittleEndianByteArray(floatvalue);
                    array[3] = temparray[0];
                    array[4] = temparray[1];
                    array[5] = temparray[2];
                    array[6] = temparray[3];
                    break;

                case "Z": // printable string 
                    temparray = Encoding.UTF8.GetBytes(field.Value);
                    temparray.CopyTo(array, 3);
                    array[3 + temparray.Length] = (byte)'\0';
                    break;
                case "H": // HexString
                    temparray = Encoding.UTF8.GetBytes(field.Value);
                    temparray.CopyTo(array, 3);
                    array[3 + temparray.Length] = (byte)'\0';
                    break;
                case "B": // integer or numeric array.
                    UpdateArrayType(array, field);
                    break;
                default:
                    throw new Exception(Properties.Resource.BAM_InvalidOptValType);
            }

            return array;
        }