public virtual bool Cancellable { get; }

Public Overridable ReadOnly Property Cancellable As Boolean
	Get

public:
virtual property bool Cancellable {
	bool get ();
}

If 'Cancellable' is true, event delegates may cancel the command that was announced by the event. To do so, a delegate would set the 'Cancel' property to True. Typically, post-events (e.g. DocumentPrinted) are not cancellable, while most pre-events (e.g. DocumentPrinting) are cancellable, except for special conditions and situations, such as when the Revit application is being closed or if an event is raised during another event.