Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

<CommandMethod("AddCircle")> _

Public Sub AddCircle()

  '' 获得当前文档和数据库   Get the current document and database

  Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument

  Dim acCurDb As Database = acDoc.Database

  ''启动一个事务   Start a transaction

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

      '' 以只读方式打开块表   Open the Block table for read

      Dim acBlkTbl As BlockTable

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

      '' 以写方式打开模型空间块表记录   Open the Block table record Model space for write

      Dim acBlkTblRec As BlockTableRecord

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

                                      OpenMode.ForWrite)

      '' 创建一个中心点在 (2,3,0) ，半径为4.25 的圆  Create a circle that is at 2,3 with a radius of 4.25

      Dim acCirc As Circle = New Circle()

      acCirc.SetDatabaseDefaults()

      acCirc.Center = New Point3d(2, 3, 0)

      acCirc.Radius = 4.25

      '' 添加新对象到块表记录和事务中   Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acCirc)

      acTrans.AddNewlyCreatedDBObject(acCirc, True)

      '' 保存新对象到数据库中   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;

using Autodesk.AutoCAD.Geometry;

[CommandMethod("AddCircle")]

public static void AddCircle()

{

  // 获得当前文档和数据库   Get the current document and database

  Document acDoc = Application.DocumentManager.MdiActiveDocument;

  Database acCurDb = acDoc.Database;

  // 启动一个事务  Start a transaction

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

  {

      // 以只读方式打开块表   Open the Block table for read

      BlockTable acBlkTbl;

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,

                                   OpenMode.ForRead) as BlockTable;

      // 以写方式打开模型空间块表记录   Open the Block table record Model space for write

      BlockTableRecord acBlkTblRec;

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

                                      OpenMode.ForWrite) as BlockTableRecord;

      // 创建一个中心点在 (2,3,0) ，半径为4.25 的圆  Create a circle that is at 2,3 with a radius of 4.25

      Circle acCirc = new Circle();

      acCirc.SetDatabaseDefaults();

      acCirc.Center = new Point3d(2, 3, 0);

      acCirc.Radius = 4.25;

      // 添加新对象到块表记录和事务中   Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acCirc);

      acTrans.AddNewlyCreatedDBObject(acCirc, true);

      // 保存新对象到数据库中   Save the new object to the database

      acTrans.Commit();

  }

}