public static byte[] DecodeHexString(String hexString)
{
if (hexString == null)
throw new ArgumentNullException( "hexString" );
bool spaceSkippingMode = false;
int i = 0;
int length = hexString.Length;
if ((length >= 2) &&
(hexString[0] == '0') &&
( (hexString[1] == 'x') || (hexString[1] == 'X') ))
{
length = hexString.Length - 2;
i = 2;
}
// Hex strings must always have 2N or (3N - 1) entries.
if (length % 2 != 0 && length % 3 != 2)
{
throw new ArgumentException( Environment.GetResourceString( "Argument_InvalidHexFormat" ) );
}
byte[] sArray;
if (length >=3 && hexString[i + 2] == ' ')
{
spaceSkippingMode = true;
// Each hex digit will take three spaces, except the first (hence the plus 1).
sArray = new byte[length / 3 + 1];
}
else
{
// Each hex digit will take two spaces
sArray = new byte[length / 2];
}
int digit;
int rawdigit;
for (int j = 0; i < hexString.Length; i += 2, j++) {
rawdigit = ConvertHexDigit(hexString[i]);
digit = ConvertHexDigit(hexString[i+1]);
sArray[j] = (byte) (digit | (rawdigit << 4));
if (spaceSkippingMode)
i++;
}
return(sArray);
}
}