WIn32API and keyboard

[mw]

Hi !

I test GetAsyncKeyState function on my XP.
Here is my code :

use Win32::API;

my $rsGetAsyncKeyState = new Win32::API("user32", "GetAsyncKeyState", "N",
"I");

sub GetAsyncKeyState {
my ($keyCode) = @_;
my $ret = $rsGetAsyncKeyState->Call($keyCode);
print "ret = $ret\n";
return( $ret & 1 );
}


while () {
sleep 1 ;
$keystate=GetAsyncKeyState(97) ;
# 97 is "a" ascii code
#print "a state=$keystate\n" ; ;
}


When I run this code and press "a" key I see only :

..
..
ret = 0
ret = 0
ret = 0
..
..
..
It means that "a" key is not pressed.
What's wrong ?

Pls help

 

[Dave]

Hi !

I test GetAsyncKeyState function on my XP.
Here is my code :

use Win32::API;

my $rsGetAsyncKeyState = new Win32::API("user32", "GetAsyncKeyState", "N",
"I");

sub GetAsyncKeyState {
my ($keyCode) = @_;
my $ret = $rsGetAsyncKeyState->Call($keyCode);
print "ret = $ret\n";
return( $ret & 1 );
}


while () {
sleep 1 ;
$keystate=GetAsyncKeyState(97) ;
# 97 is "a" ascii code
#print "a state=$keystate\n" ; ;
}


When I run this code and press "a" key I see only :

.
.
ret = 0
ret = 0
ret = 0
.
.
.
It means that "a" key is not pressed.
What's wrong ?

Pls help

I would have a look at
http://msdn.microsoft.com/library/d...e/keyboardinputfunctions/getasynckeystate.asp

especially the note for NT/2000/XP.

Also, I'm not sure what your "N" and "I" represent.

 

[Sisyphus]

Hi !

I test GetAsyncKeyState function on my XP.
Here is my code :

use Win32::API;

my $rsGetAsyncKeyState = new Win32::API("user32", "GetAsyncKeyState", "N",
"I");

sub GetAsyncKeyState {
my ($keyCode) = @_;
my $ret = $rsGetAsyncKeyState->Call($keyCode);
print "ret = $ret\n";
return( $ret & 1 );
}


while () {
sleep 1 ;
$keystate=GetAsyncKeyState(97) ;
# 97 is "a" ascii code
#print "a state=$keystate\n" ; ;
}


When I run this code and press "a" key I see only :

.
.
ret = 0
ret = 0
ret = 0
.
.
.
It means that "a" key is not pressed.
What's wrong ?

No - it means that the numeric keypad "1" key has not been pressed. (These
are "Virtual-Key" codes, not ascii codes. There should be a listing of them
somewhere on the Microsoft website.)

Press the "1" key in your numeric keypad and you'll see 'ret = 1' appear at
the next iteration of the loop.

Cheers,
Rob

 

[Robert May]

[snip code calling GetAsyncKeyState(97)]

No - it means that the numeric keypad "1" key has not been pressed. (These
are "Virtual-Key" codes, not ascii codes. There should be a listing of them
somewhere on the Microsoft website.)

URL may wrap:
http://msdn.microsoft.com/library/d...wsUserInterface/UserInput/VirtualKeyCodes.asp

97 (or 0x61) is VK_NUMERIC1
65 (or 0x41) is the 'A' key - for English layout keyboards use the ascii
code for the LOWER case letter.

Regards,
Rob.