Низкоуровневые оконные хуки - один из способов сделать это. Вот одна статья и немного больше информации от MSDN .
Это частичное представление о том, как может выглядеть этот код:
private IntPtr LowLevelKeyboardHook(int nCode, WindowsMessages wParam, [In] KBDLLHOOKSTRUCT lParam)
{
bool callNext = true;
bool isKeyDown = (wParam == WindowsMessages.KEYDOWN || wParam == WindowsMessages.SYSKEYDOWN);
bool isKeyUp = (wParam == WindowsMessages.KEYUP || wParam == WindowsMessages.SYSKEYUP);
if ((nCode >= 0) && (isKeyDown || isKeyUp))
{
// the virtual key codes and the winforms Keys have the same enumeration
// so we can freely cast back and forth between them
Keys key = (Keys)lParam.vkCode;
// Do your other processing here...
}
// if any handler returned false, trap the message
return (callNext) ? User32.CallNextHookEx(_mainHook, nCode, wParam, lParam) : _nullNext;
}
/// <summary>
/// Registers the user's LowLevelKeyboardProc with the system in order to
/// intercept any keyboard events before processed in the regular fashion.
/// This can be used to log all keyboard events or ignore them.
/// </summary>
/// <param name="hook">Callback function to call whenever a keyboard event occurs.</param>
/// <returns>The IntPtr assigned by the Windows's sytem that defines the callback.</returns>
private IntPtr RegisterLowLevelHook(LowLevelKeyboardProc hook)
{
IntPtr handle = IntPtr.Zero;
using (Process currentProcess = Process.GetCurrentProcess())
using (ProcessModule currentModule = currentProcess.MainModule)
{
IntPtr module = Kernel32.GetModuleHandle(currentModule.ModuleName);
handle = User32.SetWindowsHookEx(HookType.KEYBOARD_LL, hook, module, 0);
}
return handle;
}
/// <summary>
/// Unregisters a previously registered callback from the low-level chain.
/// </summary>
/// <param name="hook">IntPtr previously assigned to the low-level chain.
/// Users should have stored the value given by
/// <see cref="Drs.Interop.Win32.LowLevelKeyboard.RegisterLowLevelHook"/>,
/// and use that value as the parameter into this function.</param>
/// <returns>True if the hook was removed, false otherwise.</returns>
private bool UnregisterLowLevelHook(IntPtr hook)
{
return User32.UnhookWindowsHookEx(hook);
}
Просто реализуйте все необходимые объявления P / Invoke, и оно должно работать.
Я использую этот подход в своем приложении, и он отлично работает.