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

# TCustomTreeView.OnChanging

OnChanging - specialised event handler while TreeView is being changed

## Declaration

Source position: comctrls.pp line 2606

`protected property TCustomTreeView.OnChanging: TTVChangingEvent read FOnChanging write FOnChanging;`

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