public bool IsReversed {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;
}