ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Desktop.Mapping Namespace / TOCActiveMapViewProviderPane Class / OnActivate Method
True if this pane is being made the active pane, otherwise false
Version

OnActivate Method (TOCActiveMapViewProviderPane)
Called when the pane is activated (receives focus - active is true) or deactivated (loses focus - active is false).
Syntax
protected override void OnActivate( 
   bool active
)

Parameters

active
True if this pane is being made the active pane, otherwise false
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also