ArcGIS Pro 2.7 API Reference Guide
IProjectMultiItem Interface
Members  Example 

ArcGIS.Desktop.Core Namespace : IProjectMultiItem Interface
Implemented by items that support import
Syntax
public interface IProjectMultiItem 
Public Interface IProjectMultiItem 
Example
Item itemToImport = ItemFactory.Instance.Create(mxdPath);
await QueuedTask.Run(() => Project.Current.ImportItem(itemToImport as IProjectMultiItem));
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

IProjectMultiItem Members
ArcGIS.Desktop.Core Namespace