KeyboardHook.cs

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


namespace Ulavali
{
    public class KeyboardHook
    {
        private const int WhKeyboardLl = 13;
        private const int WmKeydown = 0x0100;
        private readonly LowLevelKeyboardProc _proc = HookCallback;
        private static IntPtr _hookId = IntPtr.Zero;

        public static event HandelKeyPress OnKeyPress;


        public  void SetHook()
        {
            _hookId = SetHook(_proc);
        }

        public void UnHook()
        {
            UnhookWindowsHookEx(_hookId);
        }

        private  IntPtr SetHook(LowLevelKeyboardProc proc)
        {
            using (Process curProcess = Process.GetCurrentProcess())
            using (ProcessModule curModule = curProcess.MainModule)
            {
                return SetWindowsHookEx(WhKeyboardLl, 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)WmKeydown)
            {
                int vkCode = Marshal.ReadInt32(lParam);

                OnKeyPress(vkCode);
//                Console.WriteLine((Keys)vkCode);

            }
            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);
    }

    public delegate void HandelKeyPress(int keyChar);

}