ArcGIS Pro 2.6 API Reference Guide
Update(MapView) Method
Example 

ArcGIS.Desktop.Mapping Namespace > Bookmark Class : Update(MapView) Method
The map view used to update the bookmark.
Updates the bookmark to the current location and time of a map view. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public void Update( 
   MapView mapView
)
Public Sub Update( _
   ByVal mapView As MapView _
) 

Parameters

mapView
The map view used to update the bookmark.
Exceptions
ExceptionDescription
This method or property must be called within the lambda passed to QueuedTask.Run.
Example
Update a bookmark using the active map view.
public Task UpdateBookmarkAsync(Bookmark bookmark)
{
  return QueuedTask.Run(() =>
  {
    //Get the active map view.
    var mapView = MapView.Active;
    if (mapView == null)
      return;

    //Update the bookmark using the active map view.
    bookmark.Update(mapView);
  });
}
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

Bookmark Class
Bookmark Members