Determine the Parent Object

Graphical objects are appended to a BlockTableRecord object, such as Model or Paper space. You reference the blocks that represent Model and Paper space through the BlockTable object. If you want to work in the current space instead of a specific space, you get the ObjectId for the current space from the current database with the CurrentSpaceId property.

The ObjectId for the block table records of Model and Paper space can be retrieved from the BlockTable object using a property or the GetBlockModelSpaceId and GetBlockPaperSpaceId methods of the SymbolUtilityServices class under the DatabaseServices namespace.

Access Model space, Paper space or the current space

The following example demonstrates how to access the block table records associated with Model space, Paper space or the current space. Once the block table record is referenced, a new line is added to the block table record.

VB.NET

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

Imports Autodesk.AutoCAD.EditorInput

<CommandMethod("AccessSpace")> _

Public Sub AccessSpace()

  '' Get the current document and database

  Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument

  Dim acCurDb As Database = acDoc.Database

  '' Start a transaction

  Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

      '' Open the Block table for read

      Dim acBlkTbl As BlockTable

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead)

      '' Open the Block table record for read

      Dim acBlkTblRec As BlockTableRecord

      '' Request which table record to open

      Dim pKeyOpts As PromptKeywordOptions = New PromptKeywordOptions("")

      pKeyOpts.Message = vbLf & "Enter which space to create the line in "

      pKeyOpts.Keywords.Add("Model")

      pKeyOpts.Keywords.Add("Paper")

      pKeyOpts.Keywords.Add("Current")

      pKeyOpts.AllowNone = False

      pKeyOpts.AppendKeywordsToMessage = True

      Dim pKeyRes As PromptResult = acDoc.Editor.GetKeywords(pKeyOpts)

      If pKeyRes.StringResult = "Model" Then

          '' Get the ObjectID for Model space from the Block table

          acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _

                                          OpenMode.ForWrite)

      ElseIf pKeyRes.StringResult = "Paper" Then

          '' Get the ObjectID for Paper space from the Block table

          acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.PaperSpace), _

                                          OpenMode.ForWrite)

      Else

          '' Get the ObjectID for the current space from the database

          acBlkTblRec = acTrans.GetObject(acCurDb.CurrentSpaceId, _

                                          OpenMode.ForWrite)

      End If

      '' Create a line that starts at 2,5 and ends at 10,7

      Dim acLine As Line = New Line(New Point3d(2, 5, 0), _

                                    New Point3d(10, 7, 0))

      '' Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acLine)

      acTrans.AddNewlyCreatedDBObject(acLine, True)

      '' Save the new line to the database

      acTrans.Commit()

  End Using

End Sub

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.EditorInput;

[CommandMethod("AccessSpace")]

public static void AccessSpace()

  // Get the current document and database

  Document acDoc = Application.DocumentManager.MdiActiveDocument;

  Database acCurDb = acDoc.Database;

  // Start a transaction

  using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())

      // Open the Block table for read

      BlockTable acBlkTbl;

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,

                                   OpenMode.ForRead) as BlockTable;

      // Open the Block table record for read

      BlockTableRecord acBlkTblRec;

      // Request which table record to open

      PromptKeywordOptions pKeyOpts = new PromptKeywordOptions("");

      pKeyOpts.Message = "\nEnter which space to create the line in ";

      pKeyOpts.Keywords.Add("Model");

      pKeyOpts.Keywords.Add("Paper");

      pKeyOpts.Keywords.Add("Current");

      pKeyOpts.AllowNone = false;

      pKeyOpts.AppendKeywordsToMessage = true;

      PromptResult pKeyRes = acDoc.Editor.GetKeywords(pKeyOpts);

      if (pKeyRes.StringResult == "Model")

          // Get the ObjectID for Model space from the Block table

          acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],

                                          OpenMode.ForWrite) as BlockTableRecord;

      else if (pKeyRes.StringResult == "Paper")

          // Get the ObjectID for Paper space from the Block table

          acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.PaperSpace],

                                          OpenMode.ForWrite) as BlockTableRecord;

      else

          // Get the ObjectID for the current space from the database

          acBlkTblRec = acTrans.GetObject(acCurDb.CurrentSpaceId,

                                          OpenMode.ForWrite) as BlockTableRecord;

      // Create a line that starts at 2,5 and ends at 10,7

      Line acLine = new Line(new Point3d(2, 5, 0),

                             new Point3d(10, 7, 0));

      // Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acLine);

      acTrans.AddNewlyCreatedDBObject(acLine, true);

      // Save the new line to the database

      acTrans.Commit();

VBA/ActiveX Code Reference