CreatePolygon(IEnumerable<MapPoint>,SpatialReference) Method

In This Topic

Convenience method to create a new instance of the Polygon class.

Syntax

C#
Visual Basic (Declaration)

public static Polygon CreatePolygon( 
   IEnumerable<MapPoint> points,
   SpatialReference spatialReference
)

Public Overloads Shared Function CreatePolygon( _
   ByVal points As IEnumerable(Of MapPoint), _
   Optional ByVal spatialReference As SpatialReference _
) As Polygon

Parameters

points: Points to create the polyline. Line segments are created from the coordinates of the points. The spatial references of the points 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 points which requires traversing through the enumeration of points. For improved performance, use CreatePolygon(IEnumerable<MapPoint>,AttributeFlags,SpatialReference).

Return Value

A Polygon.

Exceptions

Exception	Description
System.InvalidOperationException	Incompatible spatial references.
System.ArgumentNullException	points is null.

Remarks

The HasZ, HasM and HasID properties are inherited from which requires traversing through the enumeration of points. For improved performance, use CreatePolygon(IEnumerable<MapPoint>,AttributeFlags,SpatialReference).

Example

Builder Properties

// list of points
List<MapPoint> points = new List<MapPoint>
{
  MapPointBuilderEx.CreateMapPoint(0, 0, 2, 3, 1),
  MapPointBuilderEx.CreateMapPoint(1, 1, 5, 6),
  MapPointBuilderEx.CreateMapPoint(2, 1, 6),
  MapPointBuilderEx.CreateMapPoint(0, 0)
};

// will have attributes because it is created with convenience method
Polyline polylineWithAttrs = PolylineBuilderEx.CreatePolyline(points);
bool hasZ = polylineWithAttrs.HasZ;          // hasZ = true
bool hasM = polylineWithAttrs.HasM;          // hasM = true
bool hasID = polylineWithAttrs.HasID;        // hasID = true

// will not have attributes because it is specified as a parameter
Polyline polylineWithoutAttrs = 
  PolylineBuilderEx.CreatePolyline(points, AttributeFlags.None);
hasZ = polylineWithoutAttrs.HasZ;          // hasZ = false
hasM = polylineWithoutAttrs.HasM;          // hasM = false
hasID = polylineWithoutAttrs.HasID;        // hasID = false

// will have attributes because it is created with convenience method
Polygon polygonWithAttrs = PolygonBuilderEx.CreatePolygon(points);
hasZ = polygonWithAttrs.HasZ;               // hasZ = true
hasM = polygonWithAttrs.HasM;               // hasM = true
hasID = polygonWithAttrs.HasID;             // hasID = true

// will not have attributes because it is specified as a parameter
Polygon polygonWithoutAttrs = 
      PolygonBuilderEx.CreatePolygon(points, AttributeFlags.None);
hasZ = polygonWithoutAttrs.HasZ;               // hasZ = false
hasM = polygonWithoutAttrs.HasM;               // hasM = false
hasID = polygonWithoutAttrs.HasID;             // hasID = false

// will not have attributes because it is specified as a parameter
PolylineBuilderEx polylineB = 
           new PolylineBuilderEx(points, AttributeFlags.None);
hasZ = polylineB.HasZ;                      // hasZ = false
hasM = polylineB.HasM;                      // hasM = false
hasID = polylineB.HasID;                    // hasID = false

// will have attributes because it is passed an attributed polyline
polylineB = new PolylineBuilderEx(polylineWithAttrs);
hasZ = polylineB.HasZ;                      // hasZ = true
hasM = polylineB.HasM;                      // hasM = true
hasID = polylineB.HasID;                    // hasID = true

// will not have attributes because it is passed a non-attributed polyline
polylineB = new PolylineBuilderEx(polylineWithoutAttrs);
hasZ = polylineB.HasZ;                      // hasZ = false
hasM = polylineB.HasM;                      // hasM = false
hasID = polylineB.HasID;                    // hasID = false

// will not have attributes because it is specified as a parameter
PolygonBuilderEx polygonB = new PolygonBuilderEx(points, AttributeFlags.None);
hasZ = polygonB.HasZ;                       // hasZ = false
hasM = polygonB.HasM;                       // hasM = false
hasID = polygonB.HasID;                     // hasID = false

// will have attributes because it is passed an attributed polygon
polygonB = new PolygonBuilderEx(polygonWithAttrs);
hasZ = polygonB.HasZ;                       // hasZ = true
hasM = polygonB.HasM;                       // hasM = true
hasID = polygonB.HasID;                     // hasID = true

// will not have attributes because it is passed a non-attributed polygon
polygonB = new PolygonBuilderEx(polygonWithoutAttrs);
hasZ = polygonB.HasZ;                       // hasZ = true
hasM = polygonB.HasM;                       // hasM = true
hasID = polygonB.HasID;                     // hasID = true

Construct a Polygon - from an enumeration of MapPoints

// Use a builderEx convenience method or use a builderEx constructor.

MapPoint pt1 = MapPointBuilderEx.CreateMapPoint(1.0, 1.0);
MapPoint pt2 = MapPointBuilderEx.CreateMapPoint(1.0, 2.0);
MapPoint pt3 = MapPointBuilderEx.CreateMapPoint(2.0, 2.0);
MapPoint pt4 = MapPointBuilderEx.CreateMapPoint(2.0, 1.0);

List<MapPoint> list = new List<MapPoint>() { pt1, pt2, pt3, pt4 };

Polygon polygon = PolygonBuilderEx.CreatePolygon(list, SpatialReferences.WGS84);
// polygon.HasZ will be false - it is determined by the HasZ flag of the points in the list

// or specifically use AttributeFlags.NoAttributes
polygon = PolygonBuilderEx.CreatePolygon(list, AttributeFlags.None);

// use AttributeFlags.None as we have 2D points
PolygonBuilderEx polygonBuilder = new PolygonBuilderEx(list, AttributeFlags.None);
polygonBuilder.SpatialReference = SpatialReferences.WGS84;
polygon = polygonBuilder.ToGeometry();

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.

Reference

PolygonBuilderEx Class
PolygonBuilderEx Members
Overload List

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