Mega Code Archive
Differentiate between the two ENTER keys
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Title: differentiate between the two ENTER keys?
{
An application may find it useful to differentiate between
the user pressing the ENTER key on the standard keyboard
and the ENTER key on the numeric keypad. Either action
creates a WM_KEYDOWN message and a WM_KEYUP message with
wParam set to the virtual key code VK_RETURN. When the
application passes these messages to TranslateMessage, the
application receives a WM_CHAR message with wParam set to
the corresponding ASCII code 13.
To differentiate between the two ENTER keys, test bit 24 of
lParam sent with the three messages listed above. Bit 24 is
set to 1 if the key is an extended key; otherwise, bit 24
is set to 0 (zero).
Because the keys in the numeric keypad (along with the
function keys) are extended keys, pressing ENTER on the
numeric keypad results in bit 24 of lParam being set, while
pressing the ENTER key on the standard keyboard results in
bit 24 clear.
}
{
The following code sample demonstrates differentiating
between these two ENTER keys:
}
procedure TForm1.WMKeyDown(var Message: TWMKeyDown);
begin
inherited;
case Message.CharCode of
VK_RETURN: // ENTER pressed
if (Message.KeyData and $1000000 0) then
// Test bit 24 of lParam
ShowMessage('ENTER on numeric keypad')
else
ShowMessage('ENTER on Standard keyboard');
end;
end;
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