ArcGIS Pro 2.8 API Reference Guide
AddBookmark(MapView,String) Method
Example 

ArcGIS.Desktop.Mapping Namespace > Map Class > AddBookmark Method : AddBookmark(MapView,String) Method
The map view used to create the bookmark.
The name of the new bookmark.
Creates a new bookmark using the current location and time of the map view. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public Bookmark AddBookmark( 
   MapView mapView,
   string name
)
Public Overloads Function AddBookmark( _
   ByVal mapView As MapView, _
   ByVal name As String _
) As Bookmark

Parameters

mapView
The map view used to create the bookmark.
name
The name of the new bookmark.

Return Value

The new bookmark added to the map.
Exceptions
ExceptionDescription
The MapView must contain this Map and the name of the Bookmark must be unique for the Map.
The MapView cannot be null.
This method or property must be called within the lambda passed to QueuedTask.Run.
Example
Create a new bookmark from the active map view.
public Task<Bookmark> AddBookmarkAsync(string name)
{
  return QueuedTask.Run(() =>
  {
    //Get the active map view.
    var mapView = MapView.Active;
    if (mapView == null)
      return null;

    //Adding a new bookmark using the active view.
    return mapView.Map.AddBookmark(mapView, name);
  });
}
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Map Class
Map Members
Overload List