KeyboardHook.cs

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace KeyboardHook
{
    public class KeyboardHook
    {
        public event KeyboardHook.KeyboardHookCallback KeyDown;

        public event KeyboardHook.KeyboardHookCallback KeyUp;

        public void Install()
        {
            this.hookHandler = new KeyboardHook.KeyboardHookHandler(this.HookFunc);
            this.hookID = this.SetHook(this.hookHandler);
        }

        public void Uninstall()
        {
            KeyboardHook.UnhookWindowsHookEx(this.hookID);
        }

        private IntPtr SetHook(KeyboardHook.KeyboardHookHandler proc)
        {
            IntPtr result;
            using (ProcessModule mainModule = Process.GetCurrentProcess().MainModule)
            {
                result = KeyboardHook.SetWindowsHookEx(13, proc, KeyboardHook.GetModuleHandle(mainModule.ModuleName), 0u);
            }
            return result;
        }

        private IntPtr HookFunc(int nCode, IntPtr wParam, IntPtr lParam)
        {
            if (nCode >= 0)
            {
                int num = wParam.ToInt32();
                if ((num == 256 || num == 260) && this.KeyDown != null)
                {
                    this.KeyDown((KeyboardHook.VKeys)Marshal.ReadInt32(lParam));
                }
                if ((num == 257 || num == 261) && this.KeyUp != null)
                {
                    this.KeyUp((KeyboardHook.VKeys)Marshal.ReadInt32(lParam));
                }
            }
            return KeyboardHook.CallNextHookEx(this.hookID, nCode, wParam, lParam);
        }

        ~KeyboardHook()
        {
            this.Uninstall();
        }

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr SetWindowsHookEx(int idHook, KeyboardHook.KeyboardHookHandler 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);

        private KeyboardHook.KeyboardHookHandler hookHandler;

        private IntPtr hookID = IntPtr.Zero;

        private const int WM_KEYDOWN = 256;

        private const int WM_SYSKEYDOWN = 260;

        private const int WM_KEYUP = 257;

        private const int WM_SYSKEYUP = 261;

        public enum VKeys
        {
            NOT_A_KEY = 0,
            LBUTTON = 1,
            RBUTTON,
            CANCEL,
            MBUTTON,
            XBUTTON1,
            XBUTTON2,
            BACK = 8,
            TAB,
            CLEAR = 12,
            RETURN,
            SHIFT = 16,
            CONTROL,
            MENU,
            PAUSE,
            CAPITAL,
            KANA,
            HANGUL = 21,
            JUNJA = 23,
            FINAL,
            HANJA,
            KANJI = 25,
            ESCAPE = 27,
            CONVERT,
            NONCONVERT,
            ACCEPT,
            MODECHANGE,
            SPACE,
            PRIOR,
            NEXT,
            END,
            HOME,
            LEFT,
            UP,
            RIGHT,
            DOWN,
            SELECT,
            PRINT,
            EXECUTE,
            SNAPSHOT,
            INSERT,
            DELETE,
            HELP,
            KEY_0,
            KEY_1,
            KEY_2,
            KEY_3,
            KEY_4,
            KEY_5,
            KEY_6,
            KEY_7,
            KEY_8,
            KEY_9,
            KEY_A = 65,
            KEY_B,
            KEY_C,
            KEY_D,
            KEY_E,
            KEY_F,
            KEY_G,
            KEY_H,
            KEY_I,
            KEY_J,
            KEY_K,
            KEY_L,
            KEY_M,
            KEY_N,
            KEY_O,
            KEY_P,
            KEY_Q,
            KEY_R,
            KEY_S,
            KEY_T,
            KEY_U,
            KEY_V,
            KEY_W,
            KEY_X,
            KEY_Y,
            KEY_Z,
            LWIN,
            RWIN,
            APPS,
            SLEEP = 95,
            NUMPAD0,
            NUMPAD1,
            NUMPAD2,
            NUMPAD3,
            NUMPAD4,
            NUMPAD5,
            NUMPAD6,
            NUMPAD7,
            NUMPAD8,
            NUMPAD9,
            MULTIPLY,
            ADD,
            SEPARATOR,
            SUBTRACT,
            DECIMAL,
            DIVIDE,
            F1,
            F2,
            F3,
            F4,
            F5,
            F6,
            F7,
            F8,
            F9,
            F10,
            F11,
            F12,
            F13,
            F14,
            F15,
            F16,
            F17,
            F18,
            F19,
            F20,
            F21,
            F22,
            F23,
            F24,
            NUMLOCK = 144,
            SCROLL,
            LSHIFT = 160,
            RSHIFT,
            LCONTROL,
            RCONTROL,
            LMENU,
            RMENU,
            BROWSER_BACK,
            BROWSER_FORWARD,
            BROWSER_REFRESH,
            BROWSER_STOP,
            BROWSER_SEARCH,
            BROWSER_FAVORITES,
            BROWSER_HOME,
            VOLUME_MUTE,
            VOLUME_DOWN,
            VOLUME_UP,
            MEDIA_NEXT_TRACK,
            MEDIA_PREV_TRACK,
            MEDIA_STOP,
            MEDIA_PLAY_PAUSE,
            LAUNCH_MAIL,
            LAUNCH_MEDIA_SELECT,
            LAUNCH_APP1,
            LAUNCH_APP2,
            OEM_1 = 186,
            OEM_PLUS,
            OEM_COMMA,
            OEM_MINUS,
            OEM_PERIOD,
            OEM_2,
            OEM_3,
            OEM_4 = 219,
            OEM_5,
            OEM_6,
            OEM_7,
            OEM_8,
            OEM_102 = 226,
            PROCESSKEY = 229,
            PACKET = 231,
            ATTN = 246,
            CRSEL,
            EXSEL,
            EREOF,
            PLAY,
            ZOOM,
            NONAME,
            PA1,
            OEM_CLEAR
        }

        private delegate IntPtr KeyboardHookHandler(int nCode, IntPtr wParam, IntPtr lParam);

        public delegate void KeyboardHookCallback(KeyboardHook.VKeys key);
    }
}