ArcGIS Pro 2.6 API Reference Guide
Transparency Property (Layer)

ArcGIS.Desktop.Mapping Namespace > Layer Class : Transparency Property
Gets the transparency value set to the layer. 100 being fully transparent and 0 means opaque.
Syntax
public double Transparency {get;}
Public ReadOnly Property Transparency As Double
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

Layer Class
Layer Members