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Overview |
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Group |
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Quick Info
Windows NT
| Yes
| Win95
| Yes
| Win32s
| Yes
| Import Library
| -
| Header File
| winuser.h
| Unicode
| No
| Platform Notes
| None
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WM_SYSCHAR
The WM_SYSCHAR message is posted to the window with the keyboard focus when a WM_SYSKEYDOWN message is translated by the TranslateMessage function. It specifies the character code of a system character key  that is, a character key that is pressed while the ALT key is down.
WM_SYSCHAR
chCharCode = (TCHAR) wParam; // character code
lKeyData = lParam; // key data
Parameters
chCharCode
Value of wParam. Specifies the character code of the window menu 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
| Meaning
| 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.
| 1623
| 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.
| 2528
| 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.
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Return Values
An application should return zero if it processes this message.
Remarks
When the context code is zero, the message can be passed to the TranslateAccelerator function, which will handle it as though it were a standard key message
instead of a system character-key message. This allows accelerator keys to be used
with the active window even if the active window does not have the keyboard
focus.
For enhanced 101- and 102-key keyboards, extended keys are the right ALT and 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; the PRINT SCRN key; the BREAK key; the NUMLOCK key; and the divide (/) and ENTER keys in the numeric keypad. Other keyboards may support the extended-key bit
in the lKeyData parameter.
See Also
TranslateAccelerator, TranslateMessage, WM_SYSKEYDOWN
Related Links
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Unix Manual Pages
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