.net編寫繪制直線已完全不同于ActiveX的（VBA）的方式，過程更類似于arx程序，需要通過操作AutoCAD 數據庫添加對象！下面的代碼是在以前代碼基礎上添加了一個新myline命令。
AutoCAD 數據庫結構
myline命令代碼
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD.Geometry
Imports Autodesk.AutoCAD.Internal
Imports Autodesk.AutoCAD.Runtime
Public Class WellcomCAD
Implements IExtensionApplication
Dim acapp As AcadApplication
Public Sub Initialize() Implements IExtensionApplication.Initialize
'Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
'ed.WriteMessage("net程序已經初始化！")
'acapp = Application.AcadApplication
MsgBox("net程序已經初始化！",, "WellcomCAD")
End Sub
Public Sub Terminate() Implements IExtensionApplication.Terminate
Debug.WriteLine("net程序即將銷毀")
End Sub
<CommandMethod("Hello")>
Public Sub Hello()
Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
ed.WriteMessage("歡迎進入cad世界！")
'acapp = Application.AcadApplication
'acapp.ActiveDocument.Utility.Prompt("prompt")
End Sub
<CommandMethod("MyLine")>
Public Sub MyLine()
Dim db As Database = HostApplicationServices.WorkingDatabase
Dim Pt1 As New Point3d(0, 0, 0)
Dim Pt2 As New Point3d(300, 100, 0)
Dim LinEnt As New Line(Pt1, Pt2)
Using Trans As Transaction = db.TransactionManager.StartTransaction()
Dim Bt As BlockTable = trans.GetObject(db.BlockTableId, OpenMode.ForRead)
Dim Btr As BlockTableRecord = trans.GetObject(Bt.Item(BlockTableRecord.ModelSpace), OpenMode.ForWrite)
Btr.AppendEntity(LinEnt)
Trans.AddNewlyCreatedDBObject(LinEnt, True)
Trans.Commit()
End Using
End Sub
End Class
運行結果
