ArcGIS Pro 2.7 API Reference Guide
TOCActiveMapViewProviderPane Class
Members 

ArcGIS.Desktop.Mapping Namespace : TOCActiveMapViewProviderPane Class
Derive from TOCActiveMapViewProviderPane to continue to show the TOC of an associated MapView when your (derived) pane is activated. The MapView with the relevant TOC should be set in your Initialize override via the SetMapUri instance method.
Object Model
TOCActiveMapViewProviderPane ClassMapView ClassOperationManager ClassState ClassCIMView Class
Syntax
Remarks
Typically, consumers will derive from TOCMapPaneProviderPane instead which provides full impersonation of a MapPane and its associated MapView.

If you do use TOCActiveMapViewProviderPane then your derived class is responsible for handling any enabled state change, visibility change, etc. relevant to the MapView, whose TOC you are showing, being closed

Inheritance Hierarchy

System.Object
   ArcGIS.Desktop.Framework.Contracts.PropertyChangedBase
      ArcGIS.Desktop.Framework.Contracts.PlugIn
         ArcGIS.Desktop.Framework.Contracts.PaneBase
            ArcGIS.Desktop.Framework.Contracts.Pane
               ArcGIS.Desktop.Core.ViewStatePane
                  ArcGIS.Desktop.Mapping.TOCActiveMapViewProviderPane
                     ArcGIS.Desktop.Mapping.TOCMapPaneProviderPane

Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

TOCActiveMapViewProviderPane Members
ArcGIS.Desktop.Mapping Namespace