class ByteUtil
{

    /// <summary>
    /// converts  bytedata in a byte array to a hexadecimal string
    /// </summary>
    public static string Byte2String(byte[] b, int offset, int len, string separator)
    {
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < len; i++)
        {
            sb.AppendFormat("{0,1:X2}", b[i+offset]);
            sb.Append(separator);
        }

        return sb.ToString();
    }

    //converts hexadecimal string to a byte array
    public static byte[] String2Byte(string nstr)
    {
        string str = (string)nstr.Clone();
        str = str.Replace(" ", "");
        str = str.Replace("\t", "");

        int lenByte = str.Length / 2;
        byte[] ret = new byte[lenByte];
            
        if ((str.Length % 2) != 0) { throw new FormatException(); }

        if ( str.Length  == 0) { throw new FormatException(); }

        for (int i = 0; i < lenByte; i++)
        {
            string strByte = str.Substring(i * 2, 2);
            ret[i] = Convert.ToByte(strByte, 16);
        }
            
        return ret;
    }

}