KbdClose: Difference between revisions

Latest revision as of 03:00, 2 January 2020

This call closes the existing logical keyboard identified by the keyboard handle.

Syntax

KbdClose (KbdHandle)

Parameters

KbdHandle (HKBD) - input: Default keyboard or the logical keyboard.

Return Code

rc (USHORT) - return: Return code descriptions are:

0 - NO_ERROR
439 - ERROR_KBD_INVALID_HANDLE
464 - ERROR_KBD_DETACHED
504 - ERROR_KBD_EXTENDED_SG

Remarks

KbdClose blocks while another thread has the keyboard focus (by way of KbdGetFocus) until the thread with the focus issues KbdFreeFocus. Therefore, to prevent KbdClose from blocking, it is recommended that KbdClose be issued only while the current thread has the focus. For example:

KbdGetFocus: Wait until focus available on handle 0.
KbdClose: Close a logical keyboard handle.
KbdClose: Close another logical keyboard handle.
KbdClose: Close still another logical keyboard handle.
KbdFreeFocus: Give up the focus on handle 0.

Bindings

C

#define INCL_KBD

USHORT  rc = KbdOpen(KbdHandle);
PHKBD   KbdHandle;     /* Keyboard handle */
USHORT  rc;            /* return code */

MASM

EXTRN  KbdOpen:FAR
INCL_KBD            EQU 1

PUSH@  WORD    KbdHandle     ;Keyboard handle
CALL   KbdOpen

Returns WORD

@@ Line 5: / Line 5: @@
 ==Parameters==
-;KbdHandle (HKBD) - input : Default keyboard or the logical keyboard.
+;KbdHandle ([[HKBD]]) - input: Default keyboard or the logical keyboard.
 ==Return Code==
 ;rc (USHORT) - return:Return code descriptions are:
-* 0 - NO_ERROR
+*0 - NO_ERROR
-* 439 - ERROR_KBD_INVALID_HANDLE
+*439 - ERROR_KBD_INVALID_HANDLE
-* 464 - ERROR_KBD_DETACHED
+*464 - ERROR_KBD_DETACHED
-* 504 - ERROR_KBD_EXTENDED_SG
+*504 - ERROR_KBD_EXTENDED_SG
 ==Remarks==
-KbdClose blocks while another thread has the keyboard focus (by way of KbdGetFocus) until the thread with the focus issues KbdFreeFocus. Therefore, to prevent KbdClose from blocking, it is recommended that KbdClose be issued only while the current thread has the focus. For example:
+KbdClose blocks while another thread has the keyboard focus (by way of [[KbdGetFocus]]) until the thread with the focus issues [[KbdFreeFocus]]. Therefore, to prevent KbdClose from blocking, it is recommended that KbdClose be issued only while the current thread has the focus. For example:
 ;KbdGetFocus:Wait until focus available on handle 0.