TVM_EXPAND (Compact 2013)

3/28/2014

This message expands or collapses the list of child items, if any, associated with the specified parent item. You can send this message explicitly or by using the TreeView_Expand macro.

Syntax

TVM_EXPAND wParam = (WPARAM)(UINT) flag; 
    lParam = (LPARAM)(HTREEITEM) hitem;

Parameters

• flag
  Action flag. It is one or more of the following values.

  Value	Description
  TVE_COLLAPSE	Collapses the list.
  TVE_COLLAPSERESET	Collapses the list and removes the child items. This flag must be used with the TVE_COLLAPSE flag.
  TVE_EXPAND	Expands the list.
  TVE_EXPANDPARTIAL	Partially expands the list. In this state, the child items are visible and the parent item's plus symbol is displayed. This flag must be used in combination with the TVE_EXPAND flag.
  TVE_TOGGLE	Collapses the list if it is expanded or expands it if it is collapsed.

• hitem
  Handle to the parent item to expand or collapse.

Return Value

Nonzero indicates that a change took place. Zero indicates otherwise.

Remarks

When the TVE_EXPANDPARTIAL flag is set, the child items are visible and the plus (+) for the parent item is displayed. This flag must be used in combination with the TVE_EXPAND flag.

The TVM_EXPAND message will cause 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 TVM_EXPAND will cause the TVIS_EXPANDEDONCE state to be reset.

Requirements

See Also

Reference

Tree View Controls Messages
TreeView_Expand
TVN_ITEMEXPANDED
TVN_ITEMEXPANDING