Buffer(Geometry,Double) Method

In This Topic

Creates a buffer polygon at the specified distance around the given geometry.

Syntax

Visual Basic (Declaration)
C#

Public Overloads Function Buffer( _
   ByVal geometry As Geometry, _
   ByVal distance As Double _
) As Geometry

public Geometry Buffer( 
   Geometry geometry,
   double distance
)

Parameters

geometry: Specifies the input geometry.
distance: The distance (in the unit of the geometry's spatial reference) to buffer the geometry.

Return Value

The polygon that represents the buffered area. If the input geometry is empty, then an empty polygon is returned.

Exceptions

Exception	Description
System.ArgumentNullException	Geometry is null.
System.NotImplementedException	The method is not implemented for GeometryBag.
System.ArgumentException	The buffer distance must be a valid floating point number.

Remarks

If the buffer distance is zero and the input geometry is a polygon or an envelope, then a polygon created from the input geometry is returned.

If the distance is less than or equal to zero and the input geometry is not a polygon or an envelope, then an empty polygon is returned.

GeometryEngine Buffer

Example

Zoom to a specified point

{
  double x = -122.45;
  double y = 37.75;
  double buffer_size = 0.1;
  //Create a point
  var pt = MapPointBuilderEx.CreateMapPoint(x, y,
                 SpatialReferenceBuilder.CreateSpatialReference(4326));
  //Buffer it - for purpose of zoom
  var poly = GeometryEngine.Instance.Buffer(pt, buffer_size);

  //do we need to project the buffer polygon?
  if (!MapView.Active.Map.SpatialReference.IsEqual(poly.SpatialReference))
  {
    //project the polygon
    poly = GeometryEngine.Instance.Project(poly, MapView.Active.Map.SpatialReference);
  }

  // Must run on MCT.
  QueuedTask.Run(() =>
  {
    //Zoom - add in a delay for animation effect
    MapView.Active.ZoomTo(poly, new TimeSpan(0, 0, 0, 3));
  });
}

Buffer a MapPoint

{
  // buffer a point
  MapPoint pt = MapPointBuilderEx.CreateMapPoint(1.0, 1.0, SpatialReferences.WGS84);
  Geometry ptBuffer = GeometryEngine.Instance.Buffer(pt, 5.0);
  Polygon buffer = ptBuffer as Polygon;
}

Buffer a Circular Arc

{
  // create the circular arc
  MapPoint fromPt = MapPointBuilderEx.CreateMapPoint(2, 1);
  MapPoint toPt = MapPointBuilderEx.CreateMapPoint(1, 2);
  Coordinate2D interiorPt = new(1 + Math.Sqrt(2) / 2, 1 + Math.Sqrt(2) / 2);

  EllipticArcSegment circularArc = EllipticArcBuilderEx.CreateCircularArc(fromPt, toPt, interiorPt);

  // buffer the arc
  polyline = PolylineBuilderEx.CreatePolyline(circularArc);
  Geometry lineBuffer = GeometryEngine.Instance.Buffer(polyline, 10);
}

Requirements

Target Platforms: Windows 11 Home, Pro, Enterprise (64 bit)

ArcGIS Pro version: 3.0 or higher.

Reference

GeometryEngine Class
GeometryEngine Members
Overload List

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