public static MapView Active {get;}

public void RotateView(double heading)
{
  //Get the active map view.
  var mapView = MapView.Active;
  if (mapView == null)
    return;

  //Get the camera for the view, adjust the heading and zoom to the new camera position.
  var camera = mapView.Camera;
  camera.Heading = heading;
  mapView.ZoomToAsync(camera, TimeSpan.Zero);
}