ID Number: Q77550
3.00
WINDOWS
Summary:
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). The
contents of lParam for these messages is documented in the "Microsoft
Windows Software Development Kit Reference Volume 1."
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:
case WM_KEYDOWN:
if (wParam == VK_RETURN) // ENTER pressed
if (lParam & 0x1000000L) // Test bit 24 of lParam
{
// ENTER on numeric keypad
}
else
{
// ENTER on the standard keyboard
}
break;
Additional reference words: 3.00 SR# G911007-58 return