ArcGIS Pro 2.6 API Reference Guide
DiagramLayer Class
Members 

ArcGIS.Desktop.Mapping Namespace : DiagramLayer Class
Represents a network diagram
Object Model
DiagramLayer ClassLayer ClassCIMDataConnection ClassCIMBaseLayer ClassNetworkDiagram ClassSpatialReference ClassMap ClassILayerContainer InterfaceEnvelope Class
Syntax
Inheritance Hierarchy

System.Object
   ArcGIS.Desktop.Framework.Contracts.PropertyChangedBase
      ArcGIS.Desktop.Mapping.MapMember
         ArcGIS.Desktop.Mapping.Layer
            ArcGIS.Desktop.Mapping.CompositeLayer
               ArcGIS.Desktop.Mapping.DiagramLayer

Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

DiagramLayer Members
ArcGIS.Desktop.Mapping Namespace