Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

<CommandMethod("EraseObject")> _

Public Sub EraseObject()

  '' 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 Model space for write

      Dim acBlkTblRec As BlockTableRecord

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

                                      OpenMode.ForWrite)

      '' Create a lightweight polyline

      Dim acPoly As Polyline = New Polyline()

      acPoly.AddVertexAt(0, New Point2d(2, 4), 0, 0, 0)

      acPoly.AddVertexAt(1, New Point2d(4, 2), 0, 0, 0)

      acPoly.AddVertexAt(2, New Point2d(6, 4), 0, 0, 0)

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

      acBlkTblRec.AppendEntity(acPoly)

      acTrans.AddNewlyCreatedDBObject(acPoly, True)

      '' Update the display and display an alert message

      acDoc.Editor.Regen()

      Application.ShowAlertDialog("Erase the newly added polyline.")

      '' Erase the polyline from the drawing

      acPoly.Erase(True)

      '' Save the new object to the database

      acTrans.Commit()

  End Using

End Sub

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

[CommandMethod("EraseObject")]

public static void EraseObject()

{

  // 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 Model space for write

      BlockTableRecord acBlkTblRec;

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

                                      OpenMode.ForWrite) as BlockTableRecord;

      // Create a lightweight polyline

      Polyline acPoly = new Polyline();

      acPoly.AddVertexAt(0, new Point2d(2, 4), 0, 0, 0);

      acPoly.AddVertexAt(1, new Point2d(4, 2), 0, 0, 0);

      acPoly.AddVertexAt(2, new Point2d(6, 4), 0, 0, 0);

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

      acBlkTblRec.AppendEntity(acPoly);

      acTrans.AddNewlyCreatedDBObject(acPoly, true);

      // Update the display and display an alert message

      acDoc.Editor.Regen();

      Application.ShowAlertDialog("Erase the newly added polyline.");

      // Erase the polyline from the drawing

      acPoly.Erase(true);

      // Save the new object to the database

      acTrans.Commit();

  }

}