ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Desktop.Core Namespace / CustomProjectItemBase Class / OnAddToProject Method

OnAddToProject Method (CustomProjectItemBase)
Callback when your custom item is being added to the project
Syntax
public virtual void OnAddToProject()
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.4 or higher.
See Also