This macro expands or collapses the list of child items, if any, associated with the specified parent item. You can use this macro or send the TVM_EXPAND message explicitly.
BOOLTreeView_Expand(hwnd,hitem,flag );
Parameters
- hwnd
Handle to a tree view control. - hitem
Handle to the parent item that will be expanded or collapsed. - flag
Action flag. For a list of possible values, see the description of the flag parameter in TVM_EXPAND.Value Description TVE_EXPANDPARTIAL Child items are visible and parent item's plus symbol is displayed. This flag must be used in combination with the TVE_EXPAND flag.
Return Values
Nonzero indicates that a change took place. Zero indicates otherwise.
Remarks
The TreeView_Expand macro causes the TVN_ITEMEXPANDING and TVN_ITEMEXPANDED messages to be generated if the item being expanded does not have the TVIS_EXPANDEDONCE state bit set. This state gets set when a parent item is expanded for the first time. Using TVE_COLLAPSE and TVE_COLLAPSERESET with TreeView_Expand will cause the TVIS_EXPANDEDONCE state to be reset.
If the item already has the TVIS_EXPANDEDONCE state set, the TreeView_Expand macro does not cause the TVN_ITEMEXPANDING and TVN_ITEMEXPANDED messages to be generated.
Requirements
OS Versions: Windows CE 1.0 and later.
Header: Commctrl.h.
See Also
TVM_EXPAND | TVN_ITEMEXPANDED | TVN_ITEMEXPANDING
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