WM_VKEYTOITEM
wVkey = wParam; /* virtual-key code */
hwndLB = (HWND) LOWORD(lParam); /* handle of the list box */
nCaretPos = HIWORD(lParam); /* caret position */The WM_VKEYTOITEM message is sent by a list box with the LBS_WANTKEYBOARDINPUT style to its owner in response to a WM_KEYDOWN message.
wVkey
Value of wParam. Specifies the virtual-key code of the key that the user pressed.
hwndLB
Value of the low-order word of lParam. Identifies the list box.
nCaretPos
Value of the high-order word of lParam. Specifies the current position of the caret.
The return value specifies the action that the application performed in response to the message. A return value of –2 indicates that the application handled all aspects of selecting the item and requires no further action by the list box. A return value of –1 indicates that the list box should perform the default action in response to the keystroke. A return value of 0 or greater specifies the zero-based index of an item in the list box and indicates that the list box should perform the default action for the keystroke on the given item.
Only list boxes that have the LBS_HASSTRINGS style can receive this message.