public void SetCamera( 
   Camera camera
)

//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);
});