C# : Write and Read Binary file

using System.IO;
byte[] content = new byte[] {1, 2};
File.WriteAllBytes(@"E:\12.bin", content);
byte[] bytes = File.ReadAllBytes(@"E:\12.bin");
Console.WriteLine("{0:x3}", bytes[0]); // Hex format and 3 digits
Console.WriteLine("{0:D2}", bytes[1]); // Dec format and 2 digits