SetWindowsHookEx(WH_KEYBOARD_LL,(HOOKPROC)LowLevelKeybdProc,hDllInstance,0);

LRESULT CALLBACK LowLevelKeybdProc(int nCode,WPARAM wParam, LPARAM lParam)
{
    if (nCode == HC_ACTION)
    {
	switch(wParam)
	{
            case WM_KEYDOWN:
		DebugTrace("LowLevelKeyb...WM_KEYDOWN");
		break;
	    case WM_KEYUP:
		DebugTrace("LowLevelKeyb...WM_KEYUP");
		break;
	    case WM_SYSKEYDOWN:
		DebugTrace("LowLevelKeyb...WM_SYSKEYDOWN");
		break;
	    case WM_SYSKEYUP:
		DebugTrace("LowLevelKeyb...WM_SYSKEYUP");
		break;
	}
        ....
    }
    return CallNextHookEx (NULL, nCode, wParam, lParam) ;
}

Lässt sich zwar fehlerfrei ausführen,
aber ich bekomme wenn ich eine Taste 'normal' drücke nur
einen WM_KEYUP!!
Drücke eine Taste länger bekomme ich mehrere WM_KEYDOWN's
aber auch erst nach den WM_KEYUP's!!

Woran könnte das liegen??

Wäre für jede Hilfe dankbar.

if (nCode == HC_ACTION)

Hier ist mein Code:

static LRESULT CALLBACK LLKeyboardHookProc(int nCode, WPARAM wParam, LPARAM lParam)
{
  //if (nCode < 0)
  //  return CallNextHookEx(g_hKeyboardHook, nCode, wParam, lParam);
  static BOOL bEventSet = 0;

  PKBDLLHOOKSTRUCT pKbdStruct = reinterpret_cast<PKBDLLHOOKSTRUCT>(lParam);
  if(pKbdStruct->vkCode != VK_M)
    return 0; // return 0 = ok, return 1 = Input verwerfen

  switch (wParam)
  {
    case WM_KEYDOWN:
      switch(pKbdStruct->vkCode)
      {
        case VK_M:
          if(!bEventSet)
          {
            SetEvent(g_hEvent); // Signale Event, so that ThreadProc starts doing its job
            bEventSet = 1;
          }
          return 1;
          break;
      }
      break;
    case WM_KEYUP:
      switch(pKbdStruct->vkCode)
      {
        case VK_M:
          ResetEvent(g_hEvent); // Unsignale Event, so that ThreadProc stops doing its job
          bEventSet = 0;
          return 1;
          break;
      }
      break;
  }

  /**/
  LOG("Nachricht erhalten:\n");
  LOG("wParam = "<<wParam);
  /*
  switch (wParam)
  {
    case WM_SYSKEYDOWN:
      LOG(" WM_SYSKEYDOWN");
      break;
    case WM_SYSKEYUP:
      LOG(" WM_SYSKEYUP");
      break;
    case WM_KEYDOWN:
      LOG(" WM_KEYDOWN");
      break;
    case WM_KEYUP:
      LOG(" WM_KEYUP");
      break;
  }
  */
  LOG("vkCode = "<<pKbdStruct->vkCode<<endl);
  LOG("scCode = "<<pKbdStruct->scanCode<<endl);
  LOG("flags  = "<<pKbdStruct->flags<<( (pKbdStruct->flags & 0x10)?" injected":"" )<<endl);
  LOG("time   = "<<pKbdStruct->time<<endl);
  LOG("dwInfo = "<<pKbdStruct->dwExtraInfo<<"\n\n"<<endl);
  /**/

  return CallNextHookEx(g_hKeyboardHook, nCode, wParam, lParam); // return 0 = ok, return 1 = Input verwerfen
}

Gruss Alex.

Grüsse Alex

static LRESULT CALLBACK LLKeyboardHookProc(int nCode, WPARAM wParam, LPARAM lParam)
{
  //if (nCode < 0)
  //  return CallNextHookEx(g_hKeyboardHook, nCode, wParam, lParam);

Warum sind diese beiden Zeilen auskommentiert?

Die Platform-SDK Doku sagt dazu:

nCode
[in] Specifies a code the hook procedure uses to determine how to process the message. If nCode is less than zero, the hook procedure must pass the message to the CallNextHookEx function without further processing and should return the value returned by CallNextHookEx.

der keyboardhook gehoert in 'ne dll und nicht in das haupprog.

Der Keyboardhook ist selbstverständlich in einer dll!!