Vcl.ComCtrls.TCustomTreeView.OnExpanding
Delphi
property OnExpanding: TTVExpandingEvent read FOnExpanding write FOnExpanding;
C++
__property TTVExpandingEvent OnExpanding = {read=FOnExpanding, write=FOnExpanding};
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| event | protected | Vcl.ComCtrls.pas Vcl.ComCtrls.hpp |
Vcl.ComCtrls | TCustomTreeView |
Description
Occurs when a node is about to be expanded.
Write an OnExpanding event handler to determine whether a node can be expanded. Set the AllowExpansion parameter to false to prevent the node from expanding.
OnExpanding is an event handler of type Vcl.ComCtrls.TTVExpandingEvent.