WM_VKEYTOITEM message
Sent by a list box with the LBS_WANTKEYBOARDINPUT style to its owner in response to a WM_KEYDOWN message.
WM_VKEYTOITEM
WPARAM wParam;
LPARAM lParam;
Parameters
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wParam
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The LOWORD specifies the virtual-key code of the key the user pressed. The HIWORD specifies the current position of the caret.
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lParam
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Handle to the list box.
Return value
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. (See Remarks.) 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 index of an item in the list box and indicates that the list box should perform the default action for the keystroke on the specified item.
Remarks
A return value of -2 is valid only for keys that are not translated into characters by the list box control. If the WM_KEYDOWN message translates to a WM_CHAR message and the application processes the WM_VKEYTOITEM message generated as a result of the key press, the list box ignores the return value and does the default processing for that character). WM_KEYDOWN messages generated by keys such as VK_UP, VK_DOWN, VK_NEXT, and VK_PREVIOUS are not translated to WM_CHAR messages. In such cases, trapping the WM_VKEYTOITEM message and returning -2 prevents the list box from doing the default processing for that key.
To trap keys that generate a char message and do special processing, the application must subclass the list box, trap both the WM_KEYDOWN and WM_CHAR messages, and process the messages appropriately in the subclass procedure.
The preceding remarks apply to regular list boxes that are created with the LBS_WANTKEYBOARDINPUT style. If the list box is owner-drawn, the application must process the WM_CHARTOITEM message.
The DefWindowProc function returns -1.
If a dialog box procedure handles this message, it should cast the desired return value to a BOOL and return the value directly. The DWL_MSGRESULT value set by the SetWindowLong function is ignored.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows Vista [desktop apps only] |
| Minimum supported server |
Windows Server 2003 [desktop apps only] |
| Header |
|
See also
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Reference
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Other Resources