public bool IsExpanded {get; set;}

var elevProfileGraph = MapView.Active.GetElevationProfileGraph();
// Elevation profile graph will be null if no profile graph is displayed
if (elevProfileGraph == null)
  return;

// get the elevation profile geometry and stats
var polyline = elevProfileGraph.Geometry;
var stats = elevProfileGraph.ElevationProfileStatistics;

// reverse the graph
elevProfileGraph.IsReversed = !elevProfileGraph.IsReversed;

// collapse the graph
elevProfileGraph.IsExpanded = false;