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.
At a Glance
| Header file: | Commctrl.h |
| Windows CE versions: | 1.0 and later |
| Related message: | TVM_EXPAND |
Syntax
BOOL TreeView_Expand( hwnd, hitem, flag);
Parameters
hwndTV
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 will cause the TVN_ITEMEXPANDING and TVN_ITEMEXPANDED notification 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 will not cause the TVN_ITEMEXPANDING and TVN_ITEMEXPANDED notification messages to be generated.