ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Geometry Namespace / PolygonBuilderEx Class / CreatePolygon Method / CreatePolygon(IEnumerable<IEnumerable<Segment>>,SpatialReference) Method
Parts to create the polygon. The spatial references of the segments in the parts are checked for compatibility.
(Optional) The SpatialReference. The default value is null. If spatialReference is null, then the spatial reference will be inherited from parts which requires traversing through the enumeration of points. For improved performance, use CreatePolygon(IEnumerable<IEnumerable<Segment>>,AttributeFlags,SpatialReference).
Example Version

CreatePolygon(IEnumerable<IEnumerable<Segment>>,SpatialReference) Method
Convenience method to create a new instance of the Polygon class.
Syntax

Parameters

parts
Parts to create the polygon. The spatial references of the segments in the parts are checked for compatibility.
spatialReference
(Optional) The SpatialReference. The default value is null. If spatialReference is null, then the spatial reference will be inherited from parts which requires traversing through the enumeration of points. For improved performance, use CreatePolygon(IEnumerable<IEnumerable<Segment>>,AttributeFlags,SpatialReference).

Return Value

Exceptions
ExceptionDescription
Incompatible spatial references.
parts is null.
Remarks
The HasZ, HasM and HasID properties are inherited from parts which requires traversing through the enumeration of points. For improved performance or if you want to set these properties yourself, use CreatePolygon(IEnumerable<IEnumerable<Segment>>,AttributeFlags,SpatialReference).
Example
Create_polygon_poly
//Create a polygon graphic with simple line and fill styles.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  List<Coordinate2D> plyCoords = new List<Coordinate2D>();
  plyCoords.Add(new Coordinate2D(1, 7));
  plyCoords.Add(new Coordinate2D(2, 7));
  plyCoords.Add(new Coordinate2D(2, 6.7));
  plyCoords.Add(new Coordinate2D(3, 6.7));
  plyCoords.Add(new Coordinate2D(3, 6.1));
  plyCoords.Add(new Coordinate2D(1, 6.1));
  //At 2.x - Polygon poly = PolygonBuilder.CreatePolygon(plyCoords);
  Polygon poly = PolygonBuilderEx.CreatePolygon(plyCoords);

  //Set symbolology, create and add element to layout
  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.BlueRGB, 2.0, SimpleLineStyle.DashDotDot);
  CIMPolygonSymbol polySym = SymbolFactory.Instance.ConstructPolygonSymbol(ColorFactory.Instance.RedRGB, SimpleFillStyle.ForwardDiagonal, outline);
  //At 2.x - GraphicElement polyElm = LayoutElementFactory.Instance.CreatePolygonGraphicElement(layout, poly, polySym);
  //         polyElm.SetName("New Polygon"); 
  GraphicElement polyElm = ElementFactory.Instance.CreateGraphicElement(layout, poly, polySym, "New Polygon");
});
Create_lasso
//Create a graphic lasso element with simple line and fill styles.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  List<Coordinate2D> plyCoords = new List<Coordinate2D>();
  plyCoords.Add(new Coordinate2D(1, 1));
  plyCoords.Add(new Coordinate2D(1.25, 2));
  plyCoords.Add(new Coordinate2D(1.5, 1.1));
  plyCoords.Add(new Coordinate2D(1.75, 2));
  plyCoords.Add(new Coordinate2D(2, 1.1));
  plyCoords.Add(new Coordinate2D(2.25, 2));
  plyCoords.Add(new Coordinate2D(2.5, 1.1));
  plyCoords.Add(new Coordinate2D(2.75, 2));
  plyCoords.Add(new Coordinate2D(3, 1));
  //At 2.x - Polygon poly = PolygonBuilder.CreatePolygon(plyCoords);
  Polygon poly = PolygonBuilderEx.CreatePolygon(plyCoords);

  //Set symbolology, create and add element to layout
  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.BlackRGB, 2.0, SimpleLineStyle.Solid);
  CIMPolygonSymbol polySym = SymbolFactory.Instance.ConstructPolygonSymbol(ColorFactory.Instance.RedRGB, SimpleFillStyle.ForwardDiagonal, outline);
  //At 2.x - GraphicElement polyElm = LayoutElementFactory.Instance.CreatePolygonGraphicElement(layout, poly, polySym);
  //         polyElm.SetName("New Lasso"); 
  GraphicElement polyElm = ElementFactory.Instance.CreateGraphicElement(layout, poly, polySym, "New Lasso");
});
Create Lasso Polygon, Freehand Element
//Must be on QueuedTask.Run(() => { ...

List<Coordinate2D> plyCoords = new List<Coordinate2D>();
plyCoords.Add(new Coordinate2D(1, 1));
plyCoords.Add(new Coordinate2D(1.25, 2));
plyCoords.Add(new Coordinate2D(1.5, 1.1));
plyCoords.Add(new Coordinate2D(1.75, 2));
plyCoords.Add(new Coordinate2D(2, 1.1));
plyCoords.Add(new Coordinate2D(2.25, 2));
plyCoords.Add(new Coordinate2D(2.5, 1.1));
plyCoords.Add(new Coordinate2D(2.75, 2));
plyCoords.Add(new Coordinate2D(3, 1));
Polygon poly = PolygonBuilderEx.CreatePolygon(plyCoords);

//Set symbology, create and add element to layout
CIMStroke outline = SymbolFactory.Instance.ConstructStroke(
            ColorFactory.Instance.BlackRGB, 2.0, SimpleLineStyle.Solid);
CIMPolygonSymbol polySym = SymbolFactory.Instance.ConstructPolygonSymbol(
         ColorFactory.Instance.RedRGB, SimpleFillStyle.ForwardDiagonal, outline);

ElementFactory.Instance.CreateGraphicElement(
  container, poly, polySym, "New Lasso");
Create Polygon Element
//Must be on QueuedTask.Run(() => { ...

//Build geometry
List<Coordinate2D> plyCoords = new List<Coordinate2D>();
plyCoords.Add(new Coordinate2D(1, 7));
plyCoords.Add(new Coordinate2D(2, 7));
plyCoords.Add(new Coordinate2D(2, 6.7));
plyCoords.Add(new Coordinate2D(3, 6.7));
plyCoords.Add(new Coordinate2D(3, 6.1));
plyCoords.Add(new Coordinate2D(1, 6.1));
Polygon poly = PolygonBuilderEx.CreatePolygon(plyCoords);

//Set symbology, create and add element to layout
CIMStroke outline = SymbolFactory.Instance.ConstructStroke(
  ColorFactory.Instance.BlueRGB, 2.0, SimpleLineStyle.DashDotDot);
CIMPolygonSymbol polySym = SymbolFactory.Instance.ConstructPolygonSymbol(
  ColorFactory.Instance.RedRGB, SimpleFillStyle.ForwardDiagonal, outline);

ElementFactory.Instance.CreateGraphicElement(
  container, poly, polySym, "New Polygon", false);
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also