Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid
 
PerlMonks  

Re: Win32::API

by dada (Chaplain)
on Jul 15, 2002 at 09:57 UTC ( #181728=note: print w/ replies, xml ) Need Help??


in reply to Win32::API

Guilderstern wrote:

There are two drawbacks to Win32::API that I've noticed so far. One could be easily remedied, while the other is probably not something I should hold my breath for...

hold your breath instead :-)
I'm working on a new release of Win32::API which will make your life a lot easier by supporting not only named types (eg. WORD, DWORD et al.) but structures too.

soon (I hope) you'll be able to say:

use Win32::API 0.40; Win32::API::Struct->typedef 'POINT', qw( LONG x LONG y ); Win32::API->Import( 'user32', 'BOOL GetCursorPos(LPPOINT lpPoint)' ); my $point = Win32::API::Struct->new('POINT'); my $retval = GetCursorPos($point); print "Cursor is at $point->{x}, $point->{y}\n";
...and callbacks will be there. I'm still cleaning things up, but I bet you'll be surprised :-)

oh, and BTW:

One example I'm thinking of is placing icons in the system tray. To be able to respond to mouse clicks, the function call that places the icon there must specify a callback that gets executed on a mouse click. AFAIK, there is no way to do this yet in Perl, and it may be impossible at the present.

well, there's Win32::GUI for this.

cheers,
Aldo

__END__ $_=q,just perl,,s, , another ,,s,$, hacker,,print;


Comment on Re: Win32::API
Select or Download Code
Re: Win32::API (finally)
by dada (Chaplain) on Mar 07, 2003 at 14:17 UTC
    as promised (and after a mere 6 months or so :-), I've released version 0.40 of Win32::API.

    it may not be on CPAN at the time I write, but here's the link to download it from my site:
    Win32-API-0.40.tar.gz

    the synopsis I gave in my previous message still applies :-)

    there is even support for callbacks, but it is very experimental: feedback is appreciated as always.

    cheers,
    Aldo

    King of Laziness, Wizard of Impatience, Lord of Hubris

      Wow man, you must not really be the King of Laziness, cause this is awesome! I really appreciate your work.
      Very nice and Very handy package.
      I'm having a problem, however... :-)

      In short, I'm trying to use Win32::API to call CreateProcess.

      All is well except for the LPSTARTUPINFO and LPPROCESS_INFORMATION parms I pass into the call. If I create these using pack(...) for the correct number of bytes, it works fine and I can get the PID back out of the PROCESS_INFORMATION object (my ultimate goal).

      If, however, I create these parms using the Win32::API::Struct->new( 'STARTUPINFO' ) approach, the call fails. I'm even setting the .cb field to the size of the structure. The error I get back (using Win32::GetLastError()) is "Invalid access to memory location". Here's the function call I'm making (same in both cases):

      <-----------snip------------> # version 1 - succeeds my $si = pack( "L17", ((0) x 17) ); $si = pack( "LL16", length( $si ), ((0) x 16 ) ); my $pi = pack( "L4", ((0) x 4 ) ); # version 2 - fails my $si = Win32::API::Struct->new( "STARTUPINFO" ); $si->{cb} = $si->sizeof(); my $pi = Win32::API::Struct->new( "PROCESS_INFORMATION" ); my $retval = CreateProcess( "c:\\winnt\\notepad.exe", 0, # unused - cmdline ptr, unused 0, # unused - proc attributes ptr 0, # unused - thread attributes ptr 0, # unused - inherit handles 0, # unused - creation flags 0, # unused - env pointer 0, # unused - current dir ptr $si, $pi ); <-----------snip------------>
      Should CreateProcess be called the same way in both cases? When a ->new('STARTUPINFO') is called, is the memory zeroed-out upon creation? Any idea why the pack version succeeds and the Struct verion fails?

      TIA!
      D. Smith

        At least part of the problem is that Win32::API::Struct (or rather, Win32::API::Type) does have support for the STARTUPINFO structure, or at least not as of version 0.41 which is the latest version I can find.

        The fact that you aren't receiving the warnings I get:

        Unknown Win32::API::Struct 'STARTUPINFO' at - line 7 Can't call method "sizeof" on an undefined value at - line 8, <DATA> l +ine 164.

        means that either

        • you don't have warnings enabled.

          If so, turn them on, it'll save you much grief:)

        • You have a later version of the package than I have been able to find.

          If so, which version is it and where can I get a copy:)

        • You have a (locally?) modified copy of the package.

          If so, consult the people that made the modifications.


        Examine what is said, not who speaks.
        "Efficiency is intelligent laziness." -David Dunham
        "When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller
        If I understand your problem, I can solve it! Of course, the same can be said for you.

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://181728]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others musing on the Monastery: (2)
As of 2014-07-26 08:44 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (175 votes), past polls