I have a hexadecimal string (e.g 0CFE9E69271557822FE715A8B3E564BE) and I want to write it to a file as bytes. For example,
Offset 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
00000000 0C FE 9E 69 27 15 57 82 2F E7 15 A8 B3 E5 64 BE .þži'.W‚/ç.¨³åd¾
How can I accomplish this using .NET and C#?
This example reads 6 bytes into a byte array and writes it to another byte array. It does an XOR operation with the bytes so that the result written to the file is the same as the original starting values. The file is always 6 bytes in size, since it writes at position 0.
using System;
using System.IO;
namespace ConsoleApplication1
{
class Program
{
static void Main()
{
byte[] b1 = { 1, 2, 4, 8, 16, 32 };
byte[] b2 = new byte[6];
byte[] b3 = new byte[6];
byte[] b4 = new byte[6];
FileStream f1;
f1 = new FileStream("test.txt", FileMode.Create, FileAccess.Write);
// write the byte array into a new file
f1.Write(b1, 0, 6);
f1.Close();
// read the byte array
f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Read);
f1.Read(b2, 0, 6);
f1.Close();
// make changes to the byte array
for (int i = 1; i < b2.Length; i++)
{
b2[i] = (byte)(b2[i] ^ (byte)10); //xor 10
}
f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Write);
// write the new byte array into the file
f1.Write(b2, 0, 6);
f1.Close();
f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Read);
// read the byte array
f1.Read(b3, 0, 6);
f1.Close();
// make changes to the byte array
for (int i = 1; i < b3.Length; i++)
{
b4[i] = (byte)(b3[i] ^ (byte)10); //xor 10
}
f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Write);
// b4 will have the same values as b1
f1.Write(b4, 0, 6);
f1.Close();
}
}
}