ArcGIS Pro 2.7 API Reference Guide
SketchModifiedEvent Class
Members 

ArcGIS.Desktop.Mapping.Events Namespace : SketchModifiedEvent Class
Occurs when a sketch is modified.
Object Model
SketchModifiedEvent ClassSubscriptionToken ClassSubscriptionToken Class
Syntax
Remarks
You can Subscribe to listen for the SketchModifiedEvent and specify a delegate that will be executed upon receiving the event. To stop listening, you can Unsubscribe.

The following are examples of tools that publish the sketch events - construction tools, Edit Vertices, Align Features, Reshape.
Inheritance Hierarchy

System.Object
   ArcGIS.Core.Events.EventBase
      ArcGIS.Core.Events.CompositePresentationEvent<TPayload>
         ArcGIS.Desktop.Mapping.Events.SketchModifiedEvent

Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

SketchModifiedEvent Members
ArcGIS.Desktop.Mapping.Events Namespace