Hook Keyboard to change the key code - c++

Question

I have buy this keyboard http://www.mobilitylab.eu/mini-design-touch-silver.html of 107 touch,
and I want a keypad to put it on my left hand.
but when we activate the numlock of the keypad, it activates the numlock on the keyboard.
So we have 456- instead of uiop.
I have found this program but it don't work on a 64 bits OS. http://www.bellamyjc.org/fr/systeme.html#knumlock.
So i want to do my own program with C++, but it don't work fine, the hook is allright (WH_GETMESSAGE) but i don't understand how we can change the keycode and how we can find if it's a key of the keypad or the keybord ?
Here this is my code where i try to change the message :
//-----------------Keyboard Hook Callback---------------//
Hookmsg_API LRESULT CALLBACK Hookmsg(int ncode,WPARAM wparam,LPARAM lparam){
//if(ncode>=0) //
if(ncode<0)
return CallNextHookEx(hook,ncode,wparam,lparam);
MSG *msg;
msg=(MSG *)lparam;
WORD newVK,oldVK;
WORD newSC,oldSC;
if(ncode==HC_ACTION)
{
if((msg->message == WM_KEYUP))//Check whether key was pressed(not released).)
{
oldVK=msg->wParam;
oldSC=SCANCODE(msg->lParam);
bool extendkey=false;
if(((HIWORD(msg->wParam) & 0x0100) == 0x0100))
{
extendkey=true;
}
if(!extendkey)
{
bool modif=true;
switch(oldVK)//wparam
{
case VK_INSERT: newVK=VK_NUMPAD0; break;
case VK_END: newVK=VK_NUMPAD1; break;
case VK_DOWN: newVK=VK_NUMPAD2; break;
case VK_NEXT: newVK=VK_NUMPAD3; break;
case VK_LEFT: newVK=VK_NUMPAD4; break;
case VK_CLEAR: newVK=VK_NUMPAD5; break;
case VK_RIGHT: newVK=VK_NUMPAD6; break;
case VK_HOME: newVK=VK_NUMPAD7; break;
case VK_UP: newVK=VK_NUMPAD8; break;
case VK_PRIOR: newVK=VK_NUMPAD9; break;
case VK_DELETE: newVK=VK_DECIMAL; break;
default: modif=false;
}
if(modif==true)
{
msg->wParam = VK_NUMPAD0;
UINT newSC=MapVirtualKey(VK_NUMPAD0,MAPVK_VK_TO_VSC);
msg->lParam &= 0xFF00;
msg->lParam += (newSC << 16 );
//MessageBox( NULL, TEXT("OK"), TEXT("Error!"), MB_OK);
}
}
}
}
return ( CallNextHookEx(hook,ncode,wparam,lparam) );//pass control to next hook in the hook chain.
}

Answer 1

cant understand u...
u have 2 keyboards? if yes, try to use Raw Input (raw data from USB HID device)
http://msdn.microsoft.com/en-us/library/windows/desktop/ms645543(v=vs.85).aspx
Lparam and wparam are not visible for other applications.

Answer 2

Keyboard input is much more than just windows messages. Modifying the messages will work in some cases, but is a vastly incomplete solution. You also need to consider driver state, GetKeyboardState, and others.
If you want to remap keys on your keyboard, you can create a new keyboard layout and assign it to a locale.
If keyboard layouts don't satisfy your needs, you will need to write a keyboard device driver.
If you only need this functionality in a specific application (not system globally), then you might be able to get lucky and only modify windows messages.