ArcObjects Library Reference (Display)  

CancelTracker CoClass

Cancel tracker class for interrupting drawing.

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.

Supported Platforms

Windows, Solaris, Linux


Interfaces Description
ITrackCancel (esriSystem) Provides access to members that control the Cancel Tracker.
ITrackCancel2 (esriSystem) Provides access to members that control the Cancel Tracker.


A CancelTracker object can be retrieved through a couple of different methods (IAppDisplay::CancelTracker, IScreenDisplay::CancelTracker, and others), but it is not recommended that you attempt to use the object when obtained in this manner. The CancelTracker object used with these interfaces is for internal use.