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

# TCustomTaskDialog.OnExpanded

Event handler signalled when the ExpandedText on the dialog has been expanded or collapsed.

## Declaration

Source position: dialogs.pp line 851

`public property TCustomTaskDialog.OnExpanded : TNotifyEvent read FOnExpanded write FOnExpanded;`

## Description

OnExpanded is a TNotifyEvent property with the event handler signalled when the expanded or collapsed state for the ExpandedText area on the task dialog has been changed. OnExpanded is signalled (when assigned) from the DoOnExpandButtonClicked method, and occurs after the member for the read-only Expanded property has been updated with the new value.

Use Flags to specify the content area on the dialog where the values in ExpandedText are displayed (tfExpandFooterArea).

Use ExpandButtonCaption and CollapseButtonCaption to set the text displayed next to the expando button on the task dialog.

## Version info

Added in LCL version 4.0.

## See also

TCustomTaskDialog.Expanded |  | Indicates the expanded or collapsed state for the ExpandedText on the task dialog form.
TCustomTaskDialog.DoOnExpandButtonClicked |  | Updates the value in the Expanded property and signals the OnExpanded event handler (when assigned).
TCustomTaskDialog.ExpandButtonCaption |  | Caption displayed for the expand/collapse button on the dialog.
TCustomTaskDialog.CollapseButtonCaption |  | Caption text for the "expando" button on the task dialog.
TCustomTaskDialog.Flags |  | Set of options enabled for the Task dialog.
TTaskDialogFlags |  | Set type used to store values from the TTaskDialogFlag enumeration.
TTaskDialogFlag |  | Represents options that can be enabled for TTaskDialog.
TNotifyEvent