In this example : http://help.arcgis.com/EN/sdk/10.0/ArcObjects_NET/conceptualhelp/index.html#//000100000m6z000000
//Create source spatial reference.
Type factoryType = Type.GetTypeFromProgID("esriGeometry.SpatialReferenceEnvironment");
System.Object obj = Activator.CreateInstance(factoryType);
ISpatialReferenceFactory3 spatialReferenceFactory = obj as ISpatialReferenceFactory3;
ISpatialReference spatialReference = spatialReferenceFactory.CreateGeographicCoordinateSystem((int) esriSRGeoCSType.esriSRGeoCS_WGS1984);
spatialReference.SetFalseOriginAndUnits(-80.0000000232831, 39.9999999767169, 42949672.9);
//Create an envelope and define its spatial reference.
IEnvelope envelope = new EnvelopeClass();
envelope.PutCoords(-68.6076204314651, 49.6186709634653, -68.5531907607304, 49.6530789785679);
envelope.SpatialReference = spatialReference;
//Destination spatial reference.
ISpatialReference projectedCoordinateSystem = spatialReferenceFactory.CreateProjectedCoordinateSystem((int) esriSRProjCSType.esriSRProjCS_NAD1927UTM_19N);
//Define the XYDomain equivalent to SetFalseOriginAndUnits.
projectedCoordinateSystem.SetDomain(500000, 600000, 5300000, 5600000);
String report = "Print envelope coordinates before projection:\n" +
envelope.XMin + " , " + envelope.YMin + " , " + envelope.XMax + " , " + envelope.YMax + "\n\n\n";
//Project envelope.
IGeometry geometry = envelope as IGeometry2;
geometry.Project(projectedCoordinateSystem as ISpatialReference);
report = report + "Print envelope coordinates after projection:\n" +
envelope.XMin + " , " + envelope.YMin + " , " + envelope.XMax + " , " + envelope.YMax;
System.Windows.Forms.MessageBox.Show(report);
The input coordinates for the target envelope are : -68.6076204314651, 49.6186709634653, -68.5531907607304, 49.6530789785679Running the code provides the following output coordinates : 528323.415273589, 5496089.14621679, 532275.069518614, 5499936.46383288Displaying the input envelope on the map works - but how do I display the projected envelope in the same map?(which additional conversion is necessary?)