Re: Handling when a key is pushed

From:

"Jonathan Wood" <jwood@softcircuits.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 21 Jul 2006 15:22:50 -0600

Message-ID:

<#TStWuQrGHA.3380@TK2MSFTNGP04.phx.gbl>

It's very odd that you'd be doing it this way. You've said virtually nothing
about if this would be in a dialog or even another window. You posted this
question in an MFC group so I assume that's what you're using.

At any rate, I'm just going to assume you have some sort of window. When
that window has the focus and a key is pressed, Windows sends several
messages associated with keys. You need to catch these messages. In MFC, you
can add a handler for the window (OnKeyDown, OnChar, OnKeyUp, etc.) and
respond there.

--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com

"Jon" <TheFakeJon@gmail.com> wrote in message
news:1153514517.995337.162090@75g2000cwc.googlegroups.com...

Hello,

I was wondering how I would go about determining whether a key is
pushed.

As of now, I do something like:

long WINAPI CheckActiveKeys(long lParam) {

int result;

for(;;) {

result = ::GetAsyncKeyState(VK_SPACE);

if(result == -32767) {
MessageBox( NULL, "Space bar Pushed", "Space bar Pushed", MB_OK);
}

::Sleep(0);
}

return 0;
}

and the problem with this is that the processor polls which takes a lot
of the system resources. I was hoping to do it another way which is
not so demanding on the processor... maybe create an event or something
and when the key gets pushed, it signals an event and then I could
handle it that way?

is there any suggestions?