The WM_SYSDEADCHAR message is sent to the window with the keyboard focus when a WM_SYSKEYDOWN message is translated by the TranslateMessage function. WM_SYSDEADCHAR specifies the character code of a system dead key ¾ that is, a dead key that is pressed while holding down the ALT key.
WM_SYSDEADCHAR chCharCode = (TCHAR) wParam; // character code lKeyData = lParam; // key data
|
Value |
Description |
|
0-15 |
Specifies the repeat count for the current message. The value is the number of times the keystroke is auto-repeated as a result of the user holding down the key. If the keystroke is held long enough, multiple messages are sent. However, the repeat count is not cumulative. |
|
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. |
An application should return zero if it processes this message.
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; and the divide (/) and ENTER keys in the numeric keypad. Other keyboards may support the extended-key bit in the lKeyData parameter.