WM_DEADCHAR
WM_DEADCHAR
chCharCode = (TCHAR) wParam; // character code
lKeyData = lParam; // key data
The
WM_DEADCHAR message is posted to the window with the keyboard focus when a WM_KEYUP
Parameters
chCharCode
Value of wParam.
Specifies the character code generated by the dead key.
lKeyData
Value of lParam.
Specifies the repeat count, scan code, extended-key flag, context code,
previous key-state flag, and transition-state flag, as shown in the following
table:
Value |
Description |
0-15 |
Specifies
the repeat count. The value is the number of times the keystroke is repeated
as a result of the user holding down the key. |
16-23 |
Specifies
the scan code. The value depends on the original equipment manufacturer
(OEM). |
24 |
Specifies
whether the key is an extended key, such as the right-hand ALT and CTRL keys that
appear on an enhanced 101- or 102-key keyboard. The value is 1 if it is an
extended key; otherwise, it is 0. |
25-28 |
Reserved;
do not use. |
29 |
Specifies
the context code. The value is 1 if the ALT key is held down while the key is pressed;
otherwise, the value is 0. |
30 |
Specifies
the previous key state. The value is 1 if the key is down before the message
is sent, or it is 0 if the key is up. |
31 |
Specifies
the transition state. The value is 1 if the key is being released, or it is 0
if the key is being pressed. |
Return Values
An
application should return zero if it processes this message.
Remarks
The
WM_DEADCHAR message typically is used by applications to give the user feedback
about each key pressed. For example, an application can display the accent in
the current character position without moving the caret.
Because there
is not necessarily a one-to-one correspondence between keys pressed and
character messages generated, the information in the high-order word of the lKeyData
parameter is generally not useful to applications. The information in the
high-order word applies only to the most recent WM_KEYDOWN message that
precedes the posting of the WM_DEADCHAR message.
For enhanced
101- and 102-key keyboards, extended keys are the right ALT and the right
CTRL
keys on the main section of the keyboard; the INS, DEL, HOME, END, PAGE UP, PAGE DOWN and
arrow keys in the clusters to the left of the numeric keypad; and the divide
(/) and ENTER keys in the numeric keypad. Some other keyboards may
support the extended-key bit in the lKeyData parameter.
See Also