ArcGIS Pro 2.6 API Reference Guide
Size Property (PopupDefinition)

ArcGIS.Desktop.Mapping Namespace > PopupDefinition Class : Size Property
Gets or sets the size of the popup window. When set to null, a default size will be used. Only used when dockable is false or the dockable window is floating.
Syntax
public Nullable<Size> Size {get; set;}
Public Property Size As Nullable(Of Size)
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

PopupDefinition Class
PopupDefinition Members