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

# TCustomHeaderControl.OnSectionResize

Event handler signalled when a resize operation for a header section has been completed.

## Declaration

Source position: comctrls.pp line 4107

`published property TCustomHeaderControl.OnSectionResize : TCustomSectionNotifyEvent read FOnSectionResize write FOnSectionResize;`

## Description

OnSectionResize is a TCustomSectionNotifyEvent property with the event handler signalled when one of the header Sections has been resized by dragging the separator for the section. It is signalled (when assigned) in the SectionResize method with arguments that identify the header control and the header section for the event notification.

SectionResize / OnSectionResize occur when the left mouse button is released to complete a resizing operation. An application can implement and assign a handler routine using the signature in TCustomSectionNotifyEvent to perform actions related to the resize event for the selected section.

Use OnSectionSeparatorDblClick to handle a mouse double-click event on the section separator.

## See also

TCustomHeaderControl.SectionResize |  | Performs actions needed to resize the specified header section.
TCustomHeaderControl.Sections |  | Sections - the short segments of the header separated by vertical bars that function as the elementary selection units of the header.
TCustomHeaderControl.MouseUp |  | Signals the OnMouseUp handler.
TCustomHeaderControl.OnSectionSeparatorDblClick |  | Event handler signalled when a separator between header sections on the control is double-clicked.
TCustomSectionNotifyEvent |  | TCustomSectionNotifyEvent - generic event notification method for header section.