dll 파일의 32bit용 / 64bit 인지 여부 확인하는 함수

public static bool Is64BitDll(string dllPath)
{
	switch (GetDllMachineType(dllPath))
	{
		case MachineType.IMAGE_FILE_MACHINE_AMD64:
		case MachineType.IMAGE_FILE_MACHINE_IA64:
			return true;
		case MachineType.IMAGE_FILE_MACHINE_I386:
			return false;
		default:
			return false;
	}
}

private static MachineType GetDllMachineType(string dllPath)
{
	// See http://www.microsoft.com/whdc/system/platform/firmware/PECOFF.mspx
	// Offset to PE header is always at 0x3C.
	// The PE header starts with "PE\0\0" =  0x50 0x45 0x00 0x00,
	// followed by a 2-byte machine type field (see the document above for the enum).
	//
	FileStream fs = new FileStream(dllPath, FileMode.Open, FileAccess.Read);
	BinaryReader br = new BinaryReader(fs);
	fs.Seek(0x3c, SeekOrigin.Begin);
	Int32 peOffset = br.ReadInt32();
	fs.Seek(peOffset, SeekOrigin.Begin);
	UInt32 peHead = br.ReadUInt32();

	if (peHead != 0x00004550) // "PE\0\0", little-endian
		throw new Exception("Can't find PE header");

	MachineType machineType = (MachineType)br.ReadUInt16();
	br.Close();
	fs.Close();
	return machineType;
}