The WM_CHAR message is posted to the window with the keyboard focus when a WM_KEYDOWN message is translated by the TranslateMessage function. WM_CHAR contains the character code of the key that was pressed.
WM_CHAR
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.
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_CHAR 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.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Keyboard Input Overview, Keyboard Input Messages, TranslateMessage, WM_KEYDOWN