Through the Interface

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.Runtime;

 

namespace GeoLocationAPI

{

  public class Commands

  {

    [CommandMethod("IGR")]

    public void InsertGeoRef()

    {

      var doc = Application.DocumentManager.MdiActiveDocument;

      if (doc == null)

        return;

      var ed = doc.Editor;

      var db = doc.Database;

      var msId = SymbolUtilityServices.GetBlockModelSpaceId(db);

 

      // Check whether the drawing already has geolocation data

 

      bool hasGeoData = false;

      try

      {

        var gdId = db.GeoDataObject;

        hasGeoData = true;

      }

      catch { }

 

      if (hasGeoData)

      {

        // Report and return: could also open the object for

        // write and modify its properties, of course

 

        ed.WriteMessage("\nDrawing already has geo-location data!");

        return;

      }

 

      // Let's create some geolocation data for this drawing,

      // using a handy method to add it to the modelspace

      // (it gets added to the extension dictionary)

 

      var data = new GeoLocationData();

      data.BlockTableRecordId = msId;

      data.PostToDb();

 

      // We're going to define our geolocation in terms of

      // latitude/longitude using the Mercator projection

      // http://en.wikipedia.org/wiki/Mercator_projection

 

      data.CoordinateSystem = "WORLD-MERCATOR";

      data.TypeOfCoordinates = TypeOfCoordinates.CoordinateTypeGrid;

 

      // Use the lat-long for La Tene, my local "beach"

      // (it's on a lake, after all :-)     

 

      var geoPt = new Point3d(7.019438, 47.005247, 0);

 

      // Transform from a geographic to a modelspace point

      // and add the information to our geolocation data

 

      var wcsPt = data.TransformFromLonLatAlt(geoPt);

      data.DesignPoint = wcsPt;

      data.ReferencePoint = geoPt;

 

      // Let's launch the GEOMAP command to show our geographic

  
0;   // overlay

 

      ed.Command("_.GEOMAP", "_AERIAL");

 

      // Now we'll add a circle around our location

      // and that will provide the extents for our zoom

 

      using (var tr = db.TransactionManager.StartTransaction())

      {

        var ms =

          tr.GetObject(msId, OpenMode.ForWrite) as BlockTableRecord;

        if (ms != null)

        {

          // Add a red circle of 7K units radius

          // centred on our point

 

          var circle = new Circle(wcsPt, Vector3d.ZAxis, 7000);

          circle.ColorIndex = 1;

          ms.AppendEntity(circle);

          tr.AddNewlyCreatedDBObject(circle, true);

        }

        tr.Commit();

      }

 

      // And we'll zoom to the circle's extents

 

      ed.Command("_.ZOOM", "_OBJECT", "_L", "");

    }

  }

}