[python-win32] Re: Help on using win32api.SendMessage to send keystrokes

[Daniel F]

Wait, spoke a bit too soon. I noticed that you (Tim) apparently missed
a zero in your first method of building the bits (8 with 6 zeros
instead of 7), which generates only a 28bit number, not 32bits. (which
i blindly copy pasted at first...). when i try to make an actual 32bit
value, and then send it to the PostMessage function, i get the
following exception:

win32api.PostMessage(self.subHwnd, win32con.WM_KEYDOWN,
virtualKeyCode, keyDownBits)
OverflowError: long int too large to convert to int

as i understand it, then...  PostMessage expects exactly 32bits... and
my guess is that since python has no unsigned ints, a 32bit value
needs more than 32bits, so python makes it a long, and then
postmessage complains about longs because it expects an int-sized
value. Would that be a bug in python's implementation of PostMessage,
or am i missing something?

btw, postmessage(keydown) works just as well with a 31-bit value... so
i guess i have no problem with this, just asking out of curiosity.

Thanks,
Daniel

On Apr 1, 2005 4:19 PM, Daniel F <nanotube at gmail.com> wrote:
> Thank you all for your suggestions! Using PostMessage with
> WM_KEYDOWN/KEYUP, and creating the lparam bitfield like that, does the
> trick quite well. Really appreciate your help! :)
> 
> On Apr 1, 2005 12:59 PM, Tim Roberts <timr at probo.com> wrote:
> > On Thu, 31 Mar 2005 21:40:02 -0500, Daniel F <nanotube at gmail.com> wrote:
> >
> > >Well, i do need a general solution, I was just using notepad as a test
> > >case... So it's definitely good for me to know about this - thanks!
> > >But i wonder, isnt there some kind of an "upstream" event, that could
> > >be generated and then would automatically generate and propagate all
> > >of the keydown, char, and keyup events, so i do not have to worry
> > >about sending all three?
> > >
> > >
> >
> > You might investigate MapVirtualKey, keybd_event, and SendInput.  I have
> > no clue whether these are exposed in the Python Win32 extensions.
> > Overall, I would guess the three-message parlay is the lowest-impact method.
> >
> > >also, as to roel's earlier post... could I please have some help on
> > >how to generate a bit field in python, in order to send a well-formed
> > >lParam to SendMessage, and thus create a well-formed WM_KEYUP/KEYDOWN
> > >event?
> > >
> >
> > Python supports C expressions; you just build it by hand:
> >
> >     bits = 0x8000000 | 0x00030000 | vkKey
> >
> > Or, if you prefer the bit numbers explicitly:
> >
> >     bits = (2 << 30) | (3 << 16) | vkKey
> >
> > --
> > - Tim Roberts, timr at probo.com
> >   Providenza & Boekelheide, Inc.
> >
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> >
>