ArcGIS Pro 2.4 API Reference Guide
SetCamera(Bookmark) Method
Example 

ArcGIS.Desktop.Layouts Namespace > MapFrame Class > SetCamera Method : SetCamera(Bookmark) Method
Bookmark
Sets the map frame extent defined in a bookmark. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
Public Overloads Sub SetCamera( _
   ByVal bookmark As Bookmark _
) 
public void SetCamera( 
   Bookmark bookmark
)

Parameters

bookmark
Bookmark
Exceptions
ExceptionDescription
This method or property must be called within the lambda passed to QueuedTask.Run.
Remarks
SetCamera will have no effect a map frame's extent being driven by a map series.
Example
//Set the extent of a map frame to a bookmark.

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  //Reference MapFrame
  MapFrame mf_bk = layout.FindElement("Map Frame") as MapFrame;

  //Reference a bookmark that belongs to a map associated with the map frame
  Map m = mf_bk.Map;
  Bookmark bk = m.GetBookmarks().FirstOrDefault(item => item.Name.Equals("Lakes"));

  //Set the map frame extent using the bookmark
  mf_bk.SetCamera(bk);
});
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

MapFrame Class
MapFrame Members
Overload List