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

# TChangeLink

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

Performs notifications when images are added or deleted in TImageList.

## Declaration

Source position: imglist.pp line 71

`type TChangeLink = class(TObject)`
`public`
`destructor Destroy; override;` |  | Destructor for the class instance.
`procedure Change; virtual;` |  | Signals the OnChange event handler.
`property OnChange: TNotifyEvent; [rw]` |  | Event handler signalled for a change in the image list.
`property OnDestroyResolutionHandle: TDestroyResolutionHandleEvent; [rw]` |  | Event handler signalled when the handle for an image resolution is freed.
`property Sender: TCustomImageList; [rw]` |  | The Image list for change notifications in the class.
`end;`

## Inheritance

`TChangeLink` |  | Performs notifications when images are added or deleted in TImageList.
`TObject`

## Description

TChangeLink is a class used to perform notifications when images are added or deleted in TImageList. TChangelink provides event handlers that are signalled when the image list performs actions requiring the notification. TImageList allows multiple objects to subscribe to the change notifications, and each subscriber is represented by a TChangeLink class instance.

TChangeLink instances are passed to TCustomImageList (and descendants) in the RegisterChanges method.

## See also

TChangeLink.OnChange |  | Event handler signalled for a change in the image list.
TChangeLink.OnDestroyResolutionHandle |  | Event handler signalled when the handle for an image resolution is freed.
TCustomImageList.RegisterChanges |  | Registers a TChangeLink object for notifications when the image list is changed.
TCustomImageList.UnRegisterChanges |  | Unregisters a ChangeLink object for change notifications.
TCustomImageList.Change |  | Sends change notifications when the image list is updated.