ArcGIS Pro 2.7 API Reference Guide
Union(Envelope) Method
Example 

ArcGIS.Core.Geometry Namespace > EnvelopeBuilderEx Class : Union(Envelope) Method
The envelope with which to union. Cannot be null.
Unions the input envelope with the EnvelopeBuilder.
Syntax
public void Union( 
   Envelope envelope
)
Public Sub Union( _
   ByVal envelope As Envelope _
) 

Parameters

envelope
The envelope with which to union. Cannot be null.
Exceptions
ExceptionDescription
The input envelope is null.
Remarks
Sets the EnvelopeBuilder equal to the union of the base envelope and the input envelope. The XMin and YMin of the resulting envelope builder is the minimum XMin and YMin respectively between the base and input envelopes, and the XMax and YMax is the maximum XMax and YMax respectively between the base and input Envelopes.

Union

Example
// use the convenience builders - don't need to run on the MCT.
Envelope env1 = EnvelopeBuilder.CreateEnvelope(0, 0, 1, 1, SpatialReferences.WGS84);
Envelope env2 = EnvelopeBuilder.CreateEnvelope(0.5, 0.5, 1.5, 1.5, SpatialReferences.WGS84);

Envelope env3 = env1.Union(env2);

double area = env3.Area;
double depth = env3.Depth;
double height = env3.Height;
double width = env3.Width;
double len = env3.Length;

MapPoint centerPt = env3.Center;
Coordinate2D coord = env3.CenterCoordinate;

bool isEmpty = env3.IsEmpty;
int pointCount = env3.PointCount;

// coordinates
//env3.XMin, env3.XMax, env3.YMin, env3.YMax
//env3.ZMin, env3.ZMax, env3.MMin, env3.MMax

bool isEqual = env1.IsEqual(env2);    // false


// or use the builder constructor - need to run on the MCT.
using (var builder = new EnvelopeBuilder(0, 0, 1, 1, SpatialReferences.WGS84))
{
  env3 = builder.Union(env2);     // builder is updated to the result
  depth = builder.Depth;
  height = builder.Height;
  width = builder.Width;

  centerPt = builder.Center;
  coord = builder.CenterCoordinate;

  isEmpty = builder.IsEmpty;
}


// or use the builderEx constructors = don't need to run on the MCT.
EnvelopeBuilderEx builderEx = new EnvelopeBuilderEx(0, 0, 1, 1, SpatialReferences.WGS84);
builderEx.Union(env2);      // builder is updated to the result

depth = builderEx.Depth;
height = builderEx.Height;
width = builderEx.Width;

centerPt = builderEx.Center;
coord = builderEx.CenterCoordinate;

isEmpty = builderEx.IsEmpty;

env3 = builderEx.ToGeometry() as Envelope;
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

EnvelopeBuilderEx Class
EnvelopeBuilderEx Members