CPU Usage

yes... but I don`t know good cpp so I have not another idea..

remove while loop, instead of while use any keypress handler...event to check key...

BTW which platform are you using ?

for DOS you can use TSR Programms for such thing !

where as in windows you can write the code you have written in any kepress event...instead of while loop..

Or just try putting message dispatch loop inside while...i.e

peekmessage
translatemessage
dispatchmessage

-Anant

L@n : I suggest you use getch() or ReadConsoleInput() ( http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/readconsoleinput.asp)

I need it not only in window on my application, in every window, every game it have to decect that I pushed F12

Three main possibilites:
The easy, clean method: RegisterHotKey (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/userinput/keyboardinput/keyboardinputreference/keyboardinputfunctions/registerhotkey.asp).
Note : You have to create an hidden window for that.

Second possibility : DirectInput.
Powerful, but require learning the basics of DirectInput.

Third possibility (not a good idea).
Put Sleep(80) in your while loop (80 milliseconds is a good value).
GetAsyncKeyState, should work well for that, since it is asynchronous.

I think that the first solution is the best.

PS : I didn't know that GetAsyncKeyState, under Windows XP, was working over process boundaries... I thought it was a bug/feature only found in Windows 95/98/Me

Create a hidden (or visible) window
Call RegisterHotKey
Do a message loop, using GetMessage
Handle WM_HOTKEY messages in the WindowProc.
Quit when a when the window recieve a specific message such as WM_CLOSE.

As I said a a beginner so I will not do it :(Is it split personality that prevents you from telling beginner-in-you to use SuperKoko's advice? It's just a matter of asking more details if you don't feel confident enough with what was said.

OK, I tried to do it and it failed... The following works (don't look too close, I never wrote with bare API):#include <iostream>
#include <windows.h>

using namespace std;

#define CALL_THIS_TOOL 100
#define CLASS_NAME "Keyboard Event Catcher"

LRESULT CALLBACK WindowProcedure
(HWND hWnd, unsigned int msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_DESTROY:
PostQuitMessage(0);
return 0;
case WM_HOTKEY:
cout<<"hot key pressed!"<<endl;
return 0;
}
return DefWindowProc(hWnd,msg,wParam,lParam);
}

int main()
{
WNDCLASS wndClass;
ZeroMemory(&wndClass,sizeof(wndClass));
wndClass.lpfnWndProc = WindowProcedure;
wndClass.lpszClassName = CLASS_NAME;
if(!RegisterClass(&wndClass))
{
cout<<"can't register window class"<<endl;
}

HWND hWnd = CreateWindow(CLASS_NAME,"invisible message handler placeholder",SW_HIDE,0,0,100,100,0,0,0,0);
if(!hWnd)
{
cout<<"can't create window"<<endl;
}
RegisterHotKey(hWnd, CALL_THIS_TOOL, 0, VK_F11);


MSG msg;
int status;

while ((status = ::GetMessage (&msg,0,0,0))!=0)
{
if (status == -1)
return -1;
TranslateMessage(&msg);
DispatchMessage(&msg);
}

return 0;
}But not for F12!
There's the following paragraph in RegisterHotKey documentation:Windows NT4 and Windows 2000/XP: The F12 key is reserved for use by the debugger at all times, so it should not be registered as a hot key. Even when you are not debugging an application, F12 is reserved in case a kernel-mode debugger or a just-in-time debugger is resident.(C) http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/userinput/keyboardinput/keyboardinputreference/keyboardinputfunctions/registerhotkey.asp

And.. one more question, it is possible to use more than 1 hotkey? I don`t mean two hotkeys for example to one thing, second hotkey for some another.. soemthing like case [code]WM_HotKey2:[code]

Thanks againfor your help! it works very well, good luck in coding!

mechanism which prevents the application from being launched more than one time.

i use mutex for this.