Question

Aim :

To convert a integer value first to hexstring and then to byte[].

Example :

   Need to convert  int:1024 to hexstring:400 to byte[]: 00000100 00000000

Method:

For converting from integer to hex string i tried below code

    int i=1024;
    string hexString = i.ToString("X");

i got hexstring value as “400”. Then i tried converting hex string to byte[] using below code

    byte[] value = HexStringToByteArray(hexValue);

    /* function for converting hexstring to  byte array */
    public  byte[] HexStringToByteArray(string hex)
    {

        int NumberChars = hex.Length;

        if(NumberChars %2==1)
          throw new Exception("Hex string cannot have an odd number of digits.");

        byte[] bytes = new byte[NumberChars / 2];
        for (int i = 0; i < NumberChars; i += 2)
            bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
        return bytes;

    }

Error:

Here i got the exception “Hex String cannot have a odd number of digits”

Solution: ??

Answer 1

You can force the ToString to return a specific number of digits:

string hexString = i.ToString("X08");