ArcGIS Pro 2.8 API Reference Guide
LayoutChangedEvent Class
Members  Example 

ArcGIS.Desktop.Layouts.Events Namespace : LayoutChangedEvent Class
Occurs when the active Layout is changed.
Object Model
LayoutChangedEvent ClassSubscriptionToken ClassSubscriptionToken Class
Syntax
Remarks
Reference LayoutChangedEventArgs to get a list of arguments.
Example
//Report the event args when a layout is changed.

ArcGIS.Desktop.Layouts.Events.LayoutChangedEvent.Subscribe((args) =>
{
  System.Windows.MessageBox.Show("LayoutChangedEvent:" +
  Environment.NewLine +
  "   arg Layout: " + args.Layout.Name);
});
Inheritance Hierarchy

System.Object
   ArcGIS.Core.Events.EventBase
      ArcGIS.Core.Events.CompositePresentationEvent<TPayload>
         ArcGIS.Desktop.Layouts.Events.LayoutChangedEvent

Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

LayoutChangedEvent Members
ArcGIS.Desktop.Layouts.Events Namespace