TVN_ITEMEXPANDING notification code
Notifies a tree-view control's parent window that a parent item's list of child items is about to expand or collapse. This notification code is sent in the form of a WM_NOTIFY message.
TVN_ITEMEXPANDING
pnmtv = (LPNMTREEVIEW) lParam
Parameters
-
lParam
-
Pointer to an NMTREEVIEW structure. The itemNew member is a TVITEM structure that contains valid information about the parent item in the hItem, state, and lParam members. The action member indicates whether the list is to expand or collapse. For a list of possible values, see the description of the TVM_EXPAND message.
Return value
Returns TRUE to prevent the list from expanding or collapsing.
Requirements
Requirement | Value |
---|---|
Minimum supported client |
Windows Vista [desktop apps only] |
Minimum supported server |
Windows Server 2003 [desktop apps only] |
Header |
|
Unicode and ANSI names |
TVN_ITEMEXPANDINGW (Unicode) and TVN_ITEMEXPANDINGA (ANSI) |