ArcGIS Pro 2.7 API Reference Guide
OnDropDownOpened Method (Gallery)

ArcGIS.Desktop.Framework.Contracts Namespace > Gallery Class : OnDropDownOpened Method
Called when the gallery is expanded.
Syntax
protected internal virtual void OnDropDownOpened()
Protected Friend Overridable Sub OnDropDownOpened() 
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Gallery Class
Gallery Members