ArcGIS Pro 2.3 API Reference Guide
SetCamera(Camera) Method
Example 

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

Parameters

camera
Camera
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
//Change a map frame's camera settings.

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

  //Reference the camera associated with the map frame and change the scale
  Camera cam = mf.Camera;
  cam.Scale = 100000;

  //Set the map frame extent based on the new camera info
  mf.SetCamera(cam);
});
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

MapFrame Class
MapFrame Members
Overload List