[Overview][Constants][Types][Classes][Procedures and functions][Index] | Reference for unit 'ComCtrls' (#lcl)

# TCustomTreeView.OnCollapsed

Event handler signalled when a tree node has been collapsed on the control.

## Declaration

Source position: comctrls.pp line 3670

`protected property TCustomTreeView.OnCollapsed : TTVExpandedEvent read FOnCollapsed write FOnCollapsed;`

## Description

OnCollapsed is a TTVExpandedEvent property with the event handler signalled when a tree node has been collapsed on the tree view control. It allows the application to perform actions needed when a tree node has been collapsed - whether by using the fold indicator on the tree view or by setting the Expanded property in a TTreeNode to False.

The Sender argument contains the tree view control for the event notification.

The Node argument contains the collapsed tree node for the event.

OnCollapsed is signalled from the Collapse method, and occurs after the visibility and position in scroll bars have been updated for the control.

Use OnCollapsing to perform actions needed immediately prior to setting Expanded to False in a TTreeNode instance.

Use OnExpanded to perform actions needed when a tree node has been expanded on the tree view control.

## See also

TCustomTreeView.Collapse |  | Performs actions needed when the specified tree node is collapsed.
TCustomTreeView.CanCollapse |  | Returns True if a given TreeNode can be collapsed.
TCustomTreeView.OnCollapsing |  | Event handler signalled prior to collapsing a node on the tree view control.
TCustomTreeView.Expand |  | Expands the specified tree node and updates the scroll bars for the control.
TCustomTreeView.OnExpanded |  | Event handler signalled when a node on the tree view control has been expanded.
TTreeNode.Expanded |  | True if the node has been expanded, False when collapsed.