ArcObjects Library Reference (System)  

ITrackCancel Interface

Provides access to members that control the Cancel Tracker.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.


The CancelTracker object is the object used by ArcObjects to monitor the Esc key (optionally, the space bar and mouse clicks as well) and to terminate processes at the request of the user. A CancelTracker is typically handed into or created just prior to functions that execute a lengthy operation such as, printing, exporting and drawing.

The ITrackCancel interface provides access to properties and methods that determine if a cancellation has been executed by the user, and also allows developers to specify what actions constitute a cancellation.


Method Cancel Cancels the associated operation.
Read/write property CancelOnClick Indicates whether mouse clicks should cancel the operation.
Read/write property CancelOnKeyPress Indicates whether the escape key and spacebar should cancel the operation.
Read/write property CheckTime The interval at which the operation will be interrupted to advance progressors and process messages.
Method Continue Called frequently while associated operation is progressing. A return value of false indicates that the operation should stop.
Read/write property ProcessMessages An obsolete method.
Read/write property Progressor The progressor used to show progress during lengthy operations.
Method Reset Resets the manager after the associated operation is finished.
Method StartTimer An obsolete method.
Method StopTimer An obsolete method.
Read-only property TimerFired An obsolete method.

CoClasses that implement ITrackCancel

CoClasses and Classes Description
CancelTracker (esriDisplay) Cancel tracker class for interrupting drawing.
GPServerTrackCancel (esriGeoprocessing) GP Server Track Cancel Class.

.NET Snippets

Show Progress Dialog