ArcGIS Pro 2.6 API Reference Guide
IProjectWindow Interface
Members 

ArcGIS.Desktop.Core Namespace : IProjectWindow Interface
Use this interface to select items and retrieve the current selection
Syntax
public interface IProjectWindow 
Public Interface IProjectWindow 
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

IProjectWindow Members
ArcGIS.Desktop.Core Namespace