Through the Interface

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.Runtime;

using System.Linq;

 

namespace ConnectBlocksToCurves

{

  public static class Extensions

  {

    public static double DistanceFrom(this Curve c, Point3d pt)

    {

      return pt.DistanceTo(c.GetClosestPointTo(pt, false));

    }

 

    public static void ConnectPointToCurve(

      this Transaction tr, BlockTableRecord btr,

      Point3d pt, Curve c

    )

    {

      tr.DrawLine(btr, pt, c.GetClosestPointTo(pt, false));

    }

 

    public static void ConnectPointsToCurves(

      this Transaction tr, BlockTableRecord btr,

      Point3dCollection pts, ObjectIdCollection ids

    )

    {

      // Open all the curves and store them in an array

 

      var objs = new Curve[ids.Count];

      for (int i = 0; i < ids.Count; i++)

      {

        objs[i] = tr.GetObject(ids[i], OpenMode.ForRead) as Curve;

      }

 

      // For each point...

 

      foreach (Point3d pt in pts)

      {

        // ... we're going to sort our curves based on their distance from

        // said point

 

        var sorted =

          objs.OrderBy(

            c => c == null ? double.PositiveInfinity : c.DistanceFrom(pt)

          );

 

        // Then we're going to connect the point to the first curve in the

        // sorted list

 

        ConnectPointToCurve(tr, btr, pt, sorted.First<Curve>());

      }

    }

 

    public static void DrawLine(

      this Transaction tr, BlockTableRecord btr, Point3d pt1, Point3d pt2

    )

    {

      var ln = new Line(pt1, pt2);

      btr.AppendEntity(ln);

      tr.AddNewlyCreatedDBObject(ln, true);

    }

  }

 

  public class Commands

  {

    [CommandMethod("CBC")]

    public static void ConnectBlocksToCurves()

    {

      var doc = Application.DocumentManager.MdiActiveDocument;

      if (doc == null)

        return;

 

      var db = doc.Database;

      var ed = doc.Editor;

 

      // Get the block to connect

 

      var peo = new PromptEntityOptions("\nSelect the block");

      peo.SetRejectMessage("\nMust be a block.");

      peo.AddAllowedClass(typeof(BlockReference), false);

 

      var per = ed.GetEntity(peo);

      if (per.Status != PromptStatus.OK)

        return;

 

      // Use a dynamic object to count the blocks, rather than creating

      // a transaction etc.

 

      dynamic brId = per.ObjectId;

      ObjectIdCollection refIds =

        brId.BlockTableRecord.GetBlockReferenceIds(true, true);

 

      ed.WriteMessage("\nFound {0} references. ", refIds.Count);

 

      var pko = new PromptKeywordOptions("Connect them all?");

      pko.AllowNone = true;

      pko.Keywords.Add("Yes");

      pko.Keywords.Add("No");

      pko.Keywords.Default = "Yes";

 

      var pkr = ed.GetKeywords(pko);

      if (pkr.Status != PromptStatus.OK)

        return;

 

      // Use the same code path for a single object, just reset the collection

 

      if (pkr.StringResult != "Yes")

      {

        refIds.Clear();

        refIds.Add(brId);

      }

 

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

      {

        var btr =

          (BlockTableRecord)tr.GetObject(

            SymbolUtilityServices.GetBlockModelSpaceId(db),

            OpenMode.ForRead

          );

 

        // Collect all the Curves from the modelspace

 

        var curveIds =

          from ObjectId id in btr

          where id.ObjectClass.IsDerivedFrom(RXClass.GetClass(typeof(Curve)))

          select id;

 

        // Convert our enumerable to a ObjectIdCollection

 

        var ids = new ObjectIdCollection(curveIds.ToArray<ObjectId>());

 

        // Could also do this dynamically using...

 

        // var ptEnum = from dynamic id in refIds select (Point3d)id.Position;

        // pts = new Point3dCollection(ptEnum.ToArray<Point3d>());

 

        var pts = new Point3dCollection();

        foreach (ObjectId id in refIds)

        {

          var br = tr.GetObject(id, OpenMode.ForRead) as BlockReference;

          pts.Add(br.Position);

        }

 

        // Now we have our points and curves, connect them

 

        btr.UpgradeOpen();

        tr.ConnectPointsToCurves(btr, pts, ids);

 

        tr.Commit();

      }

    }

 

    [CommandMethod("B2C")]

    public static void Block2Curve()

    {

      var doc = Application.DocumentManager.MdiActiveDocument;

      if (doc == null)

        return;

 

      var db = doc.Database;

      var ed = doc.Editor;

 

      // Get the block to connect

 

      var peo = new PromptEntityOptions("\nSelect the block");

      peo.SetRejectMessage("\nMust be a block.");

      peo.AddAllowedClass(typeof(BlockReference), false);

 

      var per = ed.GetEntity(peo);

      if (per.Status != PromptStatus.OK)

        return;

 

      var brId = per.ObjectId;

 

      // Get the curve to connect it to

 

      var peo2 = new PromptEntityOptions("\nSelect the curve");

      peo2.SetRejectMessage("\nMust be a curve.");

      peo2.AddAllowedClass(typeof(Curve), false);

 

      var per2 = ed.GetEntity(peo2);

      if (per2.Status != PromptStatus.OK)

        return;

 

      var cId = per2.ObjectId;

 

      // Use a transaction for the geometry access and connection creation

 

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

      {

        var br = tr.GetObject(brId, OpenMode.ForRead) as BlockReference;

        var c = tr.GetObject(cId, OpenMode.ForRead) as Curve;

 

        if (br != null && c != null)

        {

          // We'll be writing to the modelspace

 

          var btr =

            (BlockTableRecord)tr.GetObject(

              SymbolUtilityServices.GetBlockModelSpaceId(db), OpenMode.ForWrite

            );

 

          // Connect the point to the closest point on the curve

 

          tr.ConnectPointToCurve(btr, br.Position, c);

        }

        tr.Commit();

      }

    }

  }

}