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

# TSizeConstraints.OnChange

Event handler signalled when a value in the class instance has been changed.

## Declaration

Source position: controls.pp line 745

`published property TSizeConstraints.OnChange : TNotifyEvent read FOnChange write FOnChange;`

## Description

OnChange is a TNotifyEvent property with the even handler signalled when one of the values in MaxHeight, MaxWidth, MinHeight, or MinWidth has been changed. OnChange is signalled (when assigned) from the Change method using the current class instance as the Sender for the notification. OnChange occurs after the modified constraints have been applied to the associated Control and its size has been adjusted.

## See also

TSizeConstraints.MaxHeight |  | The maximum height for the associated Control.
TSizeConstraints.MaxWidth |  | The maximum width for the associated Control.
TSizeConstraints.MinHeight |  | The minimum height for the associated Control.
TSizeConstraints.MinWidth |  | The minimum width for the associated Control.
TSizeConstraints.Change |  | Adjusts the size for the associated Control, and signals the OnChange handler when assigned.
TSizeConstraints.Control |  | The associated Control to which these constraints apply.
TControl.Constraints |  | Contains the minimum and maximum Width and Height for the control.
TControl.DoConstraintsChange |  | Performs actions needed when value(s) in Constraints have been changed.
TControl.AdjustSize |  | Smart way to DoAutoSize.