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4/8/2010

This message is posted to the window with the keyboard focus when a nonsystem key is released. A nonsystem key is a 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.

Syntax 

WM_KEYUP 
nVirtKey = (int) 
wParam; 

lKeyData = 
lParam;

Parameters

nVirtKey

Specifies the virtual-key code of the nonsystem key.

lKeyData

Specifies the repeat count, 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. This value depends on the original equipment manufacturer.

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 Value

An application should return zero if it processes this message.

Default Action

The DefWindowProcfunction sends a WM_SYSCOMMANDmessage to the top-level window if the F10 key or the ALT key was released. The wParamparameter of the message is set to SC_KEYMENU.

Remarks

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 lKeyDataparameter.

Requirements

Header winuser.h
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also