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

# TCustomComboBox.OnChange

Event handler signalled for user changes to the text in the edit box.

## Declaration

Source position: stdctrls.pp line 397

`protected property TCustomComboBox.OnChange : TNotifyEvent read FOnChange write FOnChange;`

## Description

OnChange is a TNotifyEvent property which implements the event handler signalled when the value in the edit box has been changed.

The event applies to interactive changes to Text made by the user, not those made programmatically. Note that this differs from how other OnChange events work. For example: TEdit.OnChange is triggered by text changes that occur in code. This event is also triggered when the item selection is changed using the drop-down list in the combo-box.

OnChange is signalled (when assigned) in the Change method called when the control messages are handled in the window procedure. An application must implement and assign an object procedure using the signature in TNotifyEvent to respond to the event notification.

## See also

TCustomEdit.OnChange |  | Event handler signalled when the text for the control is changed.
TCustomEdit.Change |  | Performs actions needed when the text in the control is changed.
TCustomEdit.Text |  | The text displayed and edited for the control.
TNotifyEvent