LowLevelHook.cs

using System;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

/// <summary>
/// Low Level mouse and keyboard hook wrapper
/// Made by BahNahNah
/// </summary>
public class LowLevelHook
{
    #region " Delegates "

    private delegate IntPtr LowLevelHookCallback(int nCode, IntPtr wParam, IntPtr lParam);
    public delegate void LLKeyboardHook(string hKey, LowLevelKeyboardParameter parameter);
    public delegate void LLMouseHook(LowLevelMouseButtons button, LLMouseLocation location);

    #endregion

    #region " Events "

    public static event LLKeyboardHook KeyboardEvent;
    public static event LLMouseHook MouseEvent;

    #endregion

    #region " Values "

    private static bool LShiftPress = false;
    private static bool RShiftPress = false;
    private static bool CapsPressed = false;

    static LowLevelHookCallback KBCallback = new LowLevelHookCallback(LLKeyboardCallback);
    static LowLevelHookCallback MCallback = new LowLevelHookCallback(LLMouseCallback);

    #endregion

    #region " Hooks "

    static IntPtr KBHook = IntPtr.Zero;
    static IntPtr MHook = IntPtr.Zero;

    #endregion

    #region " Functions "

    /// <summary>
    /// Apply Low level hook to keyboard
    /// </summary>
    public static void HookKeyboard()
    {
        if (KBHook != IntPtr.Zero)
            throw new Exception("Keyboard is alredy hooked.");
        KBHook = SetWindowsHookEx(13, KBCallback, IntPtr.Zero, 0);
    }
    /// <summary>
    /// Apply Low level hook to mouse
    /// </summary>
    public static void HookMouse()
    {
        if (MHook != IntPtr.Zero)
            throw new Exception("Keyboard is alredy hooked.");
        MHook = SetWindowsHookEx(14, MCallback, IntPtr.Zero, 0);
    }

    /// <summary>
    /// Remove low level hook from keyboard
    /// </summary>
    public static void UnhookKeyboard()
    {
        if (UnhookWindowsHookEx(KBHook))
            KBHook = IntPtr.Zero;
    }
    /// <summary>
    /// Remove low level hook from mouse
    /// </summary>
    public static void UnhookMouse()
    {
        if (UnhookWindowsHookEx(MHook))
            MHook = IntPtr.Zero;
    }

    #endregion

    #region " Callbacks "

    private static IntPtr LLKeyboardCallback(int nCode, IntPtr wParam, IntPtr lParam)
    {
        if (nCode > -1 && KeyboardEvent != null)
        {
            LLKeyboardHook call = KeyboardEvent;
            LowLevelKeyboardParameter p = (LowLevelKeyboardParameter)wParam;
            Keys key = (Keys)Marshal.ReadInt32(lParam);
            if (key == Keys.LShiftKey) LShiftPress = (p == LowLevelKeyboardParameter.KeyDown);
            if (key == Keys.RShiftKey) RShiftPress = (p == LowLevelKeyboardParameter.KeyDown);
            if (key == Keys.CapsLock) CapsPressed = (p == LowLevelKeyboardParameter.KeyDown);
            string v = (LShiftPress || RShiftPress || CapsPressed) ? key.ToString() : key.ToString().ToLower();
            call(v, p);
        }
        return CallNextHookEx(KBHook, nCode, wParam, lParam);
    }

    private static IntPtr LLMouseCallback(int nCode, IntPtr wParam, IntPtr lParam)
    {
        if (nCode > -1 && MouseEvent != null)
        {
            LLMouseHook call = MouseEvent;
            LowLevelMouseButtons b = (LowLevelMouseButtons)wParam;
            LLMouseLocation location = (LLMouseLocation)Marshal.PtrToStructure(lParam, typeof(LLMouseLocation));
            call(b, location);
        }
        return CallNextHookEx(KBHook, nCode, wParam, lParam);
    }

    #endregion

    #region " WinApi "

    [DllImport("user32.dll", SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelHookCallback lpfn, IntPtr hMod, uint dwThreadId);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern bool UnhookWindowsHookEx(IntPtr hhk);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll")]
    private static extern int ToUnicodeEx(uint key, uint scancode, byte[] keyState, StringBuilder buffer, int bufferSuise, uint flags, IntPtr kblout);

    [DllImport("user32.dll")]
    private static extern bool GetKeyboardState(byte[] buffer);

    [DllImport("user32.dll")]
    private static extern int GetAsyncKeyState(int vkCode);

    [DllImport("user32.dll")]
    static extern IntPtr GetKeyboardLayout(uint idThread);


    #endregion
}
public enum LowLevelKeyboardParameter
{
    KeyDown = 0x100,
    KeyUp = 0x101,
    SysKeyDown = 0x104,
    SysKeyUp = 0x105
}


public enum LowLevelMouseButtons
{
    MOVE = 0x200,
    LDOWN = 0x201,
    LUP = 0x202,
    RDOWN = 0x204,
    RUP = 0x205,
    MWheel = 0x20A,
    MHWheel = 0x20E
}
public struct LLMouseLocation
{
    int _X;
    int _Y;
    public int X { get { return _X; } }
    public int Y { get { return _Y; } }
    public override string ToString()
    {
        return string.Format("({0},{1})", X, Y);
    }
}