Keyboard events handler for C# WinForms application

Question

Hi,

how can I do global keyboard event handler for C# winform application? I think it should be a separate class with some methods and events, but I do not know exactely how to do this. Global handler should provide funcionallity to catch key pressed (for handling shortcuts).

best regards

Answer 1

May be keyboard hook will be usefull?

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace hook
{
    class Program
    {
        private const int WH_KEYBOARD_LL = 13;
        private const int WM_KEYDOWN = 0x0100;
        private static LowLevelKeyboardProc _proc = HookCallback;
        private static IntPtr _hookID = IntPtr.Zero;

        static void Main()
        {
            _hookID = SetHook(_proc);
            Application.Run();
            UnhookWindowsHookEx(_hookID);

        }

        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);
                if (((Keys)vkCode == Keys.LWin) || ((Keys)vkCode == Keys.RWin))
                {
                    Console.WriteLine("{0} blocked!", (Keys)vkCode);
                    return (IntPtr)1;
                }
            }
            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)]
        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);

    
    
    }
}

Answer 2

you can also use this Post from MS

http://support.microsoft.com/kb/320584

Answer 3

HI

http://www.codeproject.com/KB/cs/globalhook.aspx

thank you