REFERENCE GUIDE

WM_CHARCommentsIParamContains the repeat count, scan code, key-transition code,previous key state, and context code, as shown in the followinglist:BitValue0-15 Repeat count (the number of times the(low-order word) key stroke is repeated as a result of the userholding down the key).Scan code (OEM-dependent value).16-23(low byte ofhigh-order word)2425-2627-28293031Extended key, such as a function key or akey on the numeric keypad (1 if it is anextended key).Not used.Used internally by Windows.Context code (1 if the AL T key is held downwhile the key is pressed, 0 otherwise).Previous key state (1 if the key is downbefore the message is sent, 0 if the key isup).Transition state (1 if the key is beingreleased, 0 if the key is being pressed).Since there is not necessarily a one-to-one correspondence between keyspressed and character messages generated, the information in the highorderword of the IParam parameter is generally not useful to applications.The information in the high-order word applies only to the most recentWM_KEYUP or WM_KEYDOWN message that precedes the posting ofthe character message.For IBM® Enhanced 101- and 102-key keyboards, enhanced keys are theright ALT and the right CONTROL keys on the main section of the keyboard;the INSERT, DELETE, HOME, END, PAGE UP, PAGE DOWN and DIRECTION keysin the clusters to the left of the numeric key pad; and the divide U) andENTER keys in the numeric key pad. Some other keyboards may supportthe extended-key bit in the IParam parameter.WM_CHARTOITEM 3.0This message is sent by a list box with the LBS_WANTKEYBOARDINPUTstyle to its owner in response to a WM_ CHAR message.Parameters wParam Contains the value of the key which the user pressed.642Software development kit