WM_KEYUP

WM_KEYUP

nVirtKey = (int) wParam; /* virtual-key code */

lKeyData = lParam; /* key data */

The WM_KEYUP message is posted to the window with the keyboard focus when a nonsystem key is released. A nonsystem key is a keyboard key that is pressed when the ALT key is not pressed, or a keyboard key that is pressed when a window has the keyboard focus.

Parameters

nVirtKey

Value of wParam. Specifies the virtual-key code of the nonsystem 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. The repeat count is always one for a WM_KEYUP message.
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 a function key or a key on the numeric key pad. The value is 1 if it is an extended key; otherwise, it is 0.
25–28 Reserved.
29 Specifies the context code. The value is always 0 for a WM_KEYUP message.
30 Specifies the previous key state. The value is always 1 for a WM_KEYUP message.
31 Specifies the transition state. The value is always 1 for a WM_KEYUP message.

Return Value

An application should return zero if it processes this message.

Comments

For IBM Enhanced 101- and 102-key keyboards, extended keys are the right ALT and the right CONTROL keys on the main section of the keyboard; the INSERT, DELETE, HOME, END, PAGE UP, PAGE DOWN and DIRECTION keys in the clusters to the left of the numeric key pad; and the divide (/) and ENTER keys in the numeric key pad. Some other keyboards may support the extended-key bit in the lKeyData parameter.

See Also

WM_KEYDOWN