public static GraphicElement AddElement( 
   GraphicsLayer graphicsLayer,
   CIMGraphic cimGraphic,
   string elementName,
   bool select,
   ElementInfo elementInfo
)

{
  var pointSymbol = SymbolFactory.Instance.ConstructPointSymbol(ColorFactory.Instance.BlackRGB, 8);
  var graphicsLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<GraphicsLayer>().FirstOrDefault();
  //Note: Must be on QueuedTask.Run

  //Get a point in the center of the Map frame
  var mapFrameCenterPoint = mapFrame.GetBounds().CenterCoordinate;
  //Convert to MapPoint
  var pointInMapFrame = MapPointBuilderEx.CreateMapPoint(mapFrameCenterPoint);

  //Find the corresponding point in the MapView
  var pointOnMap = mapFrame.PageToMap(pointInMapFrame);

  //Create a point graphic on the MapView.
  var cimGraphicElement = new CIMPointGraphic
  {
    Location = pointOnMap,
    Symbol = pointSymbol.MakeSymbolReference()
  };
  graphicsLayer.AddElement(cimGraphicElement);
}

{
  // Note: must be called on the QueuedTask
  {
    //Place symbol in the center of the map
    var extent = MapView.Active.Extent;
    var location = extent.Center;

    //specify a symbol
    var pt_symbol = SymbolFactory.Instance.ConstructPointSymbol(
                          ColorFactory.Instance.GreenRGB);

    //create a CIMGraphic 
    var graphic = new CIMPointGraphic()
    {
      Symbol = pt_symbol.MakeSymbolReference(),
      Location = location //center of map
    };
    graphicsLayer.AddElement(graphic);
  }
}

{
  // Note: must be called on the QueuedTask
  {
    //On the QueuedTask
    //Place a line symbol using the extent's lower left and upper right corner.
    var extent = MapView.Active.Extent;
    //get the lower left corner of the extent
    var pointFromCoordinates = new Coordinate2D(extent.XMin, extent.YMin);
    //get the upper right corner of the extent
    var pointToCoordinates = new Coordinate2D(extent.XMax, extent.YMax);
    List<Coordinate2D> points = new List<Coordinate2D> { pointFromCoordinates, pointToCoordinates };
    //create the polyline
    var lineSegment = PolylineBuilderEx.CreatePolyline(points);

    //specify a symbol
    var line_symbol = SymbolFactory.Instance.ConstructLineSymbol(
                          ColorFactory.Instance.GreenRGB);
    //create a CIMGraphic 
    var graphic = new CIMLineGraphic()
    {
      Symbol = line_symbol.MakeSymbolReference(),
      Line = lineSegment,
    };
    graphicsLayer.AddElement(graphic);
  }
}

{
  // Note: must be called on the QueuedTask
  {
    //On the QueuedTask
    //Place a polygon symbol using the mapview extent geometry
    var extent = MapView.Active.Extent;
    //Contract the extent
    var polygonEnv = extent.Expand(-100000, -90000, false);
    //create a polygon using the envelope
    var polygon = PolygonBuilderEx.CreatePolygon(polygonEnv);

    //specify a symbol
    var poly_symbol = SymbolFactory.Instance.ConstructPolygonSymbol(
                          ColorFactory.Instance.GreenRGB);

    //create a CIMGraphic 
    var graphic = new CIMPolygonGraphic()
    {
      Symbol = poly_symbol.MakeSymbolReference(),
      Polygon = polygon,
    };
    graphicsLayer.AddElement(graphic);
  }
}

{
  // Note: must be called on the QueuedTask
  {
    //Place a multipoint graphic using the mapview extent geometry
    var extent = MapView.Active.Extent;
    //Contract the extent
    var polygonEnv = extent.Expand(-100000, -90000, false);
    //create a polygon using the envelope
    var polygon = PolygonBuilderEx.CreatePolygon(polygonEnv);
    //Create MultipPoints from the polygon
    var multiPoints = MultipointBuilderEx.CreateMultipoint(polygon);
    //specify a symbol
    var point_symbol = SymbolFactory.Instance.ConstructPointSymbol(
                          ColorFactory.Instance.GreenRGB);
    //create a CIMGraphic 
    var graphic = new CIMMultipointGraphic
    {
      Symbol = point_symbol.MakeSymbolReference(),
      Multipoint = multiPoints
    };
    graphicsLayer.AddElement(graphic);
  }
}

{
  // Note: must be called on the QueuedTask
  {
    //Place symbol in the center of the map
    var extent = MapView.Active.Extent;
    var location = extent.Center;

    //specify a symbol
    var pt_symbol = SymbolFactory.Instance.ConstructPointSymbol(
                          ColorFactory.Instance.GreenRGB);
    graphicsLayer.AddElement(location, pt_symbol);
  }
}

{
  // Note: must be called on the QueuedTask
  {
    //Place symbol in the center of the map
    var extent = MapView.Active.Extent;
    var location = extent.Center;

    //specify a text symbol
    var text_symbol = SymbolFactory.Instance.ConstructTextSymbol
    (ColorFactory.Instance.BlackRGB, 8.5, "Corbel", "Regular");

    graphicsLayer.AddElement(location, text_symbol, "Text Example");
  }
}