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

# TCustomDrawGrid.OnHeaderSizing

Event handler signalled when a column or row header sizing action is started.

## Declaration

Source position: grids.pas line 1564

`public property TCustomDrawGrid.OnHeaderSizing : THeaderSizingEvent read FOnHeaderSizing write FOnHeaderSizing;`

## Description

OnHeaderSizing is a THeaderSizingEvent property with the event handler signalled when a column or row header sizing action is started. It is signalled (when assigned) from the HeaderSizing method, and occurs when MouseMove events are handled when the internal grid state is set to gsColSizing or gsRowSizing.

## See also

TCustomDrawGrid.HeaderSizing |  | Performs actions when resizing a column or row to the specified size.
TCustomDrawGrid.OnHeaderSized |  | Event handler signalled when a column or row header has been resized.
TCustomGrid.MouseMove |  | Applies a change in the mouse pointer position to the grid control.
THeaderSizingEvent |  | Specifies an event handler signalled when a fixed cell header in a grid is resized.
TGridState |  | Enumerated type with grid state values.