Create a Circle Object (.NET)

This example creates a circle in Model space with a center point of (2,3,0) and a radius of 4.25.

VB.NET

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
 
<CommandMethod("AddCircle")> _
Public Sub AddCircle()
    '' 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 circle that is at 2,3 with a radius of 4.25
        Using acCirc As Circle = New Circle()
            acCirc.Center = New Point3d(2, 3, 0)
            acCirc.Radius = 4.25

            '' Add the new object to the block table record and the transaction
            acBlkTblRec.AppendEntity(acCirc)
            acTrans.AddNewlyCreatedDBObject(acCirc, True)
        End Using

        '' Save the new object to the database
        acTrans.Commit()
    End Using
End Sub

C#

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
 
[CommandMethod("AddCircle")]
public static void AddCircle()
{
    // 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 circle that is at 2,3 with a radius of 4.25
        using (Circle acCirc = new Circle())
        {
            acCirc.Center = new Point3d(2, 3, 0);
            acCirc.Radius = 4.25;

            // Add the new object to the block table record and the transaction
            acBlkTblRec.AppendEntity(acCirc);
            acTrans.AddNewlyCreatedDBObject(acCirc, true);
        }

        // Save the new object to the database
        acTrans.Commit();
    }
}

VBA/ActiveX Code Reference

Sub AddCircle()
    ' Define the center point
    Dim ptCen(0 To 2) As Double
    ptCen(0) = 2: ptCen(1) = 3: ptCen(2) = 0#
 
    ' Create a Circle object in model space
    Dim circObj As AcadCircle
    Set circObj = ThisDrawing.ModelSpace.AddCircle(ptCen, 4.25)
 
    ThisDrawing.Application.ZoomAll
End Sub