Question

Imports System.Drawing
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD.ApplicationServices.DocumentExtension

    Namespace sweeping
        Public Class Testing
            <CommandMethod("jointwolines")>
            Public Shared Sub jointwolines()


                Dim line1, line2 As Line
                Dim pll As polyline


                Dim doc As Document = Application.DocumentManager.MdiActiveDocument
                Dim db As Database = doc.Database
                Dim ed As Editor = doc.Editor
                Dim bt As BlockTable
                Dim btr As BlockTableRecord

                Using tr As Transaction = db.TransactionManager.StartTransaction()

                    line1 = New line(New point3d(0, 0, 0), New point3d(100, 0, 0))
                    line2 = New line(New point3d(100, 0, 0), New point3d(100, 100, 0))

                    bt = tr.GetObject(db.BlockTableId, OpenMode.ForRead)
                    btr = tr.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForWrite)
                    pll = line1.joinentity(line2)

                    btr.AppendEntity(pll)
                    tr.AddNewlyCreatedDBObject(pll, True)
                    tr.Commit()

                End Using
            End Sub
        End Class
    End Namespace

我的autocad自定义部分要求我将两行连接到一个实体中。我一直在努力完成它。但是，我面临一些障碍。

第一个： pll = line1.joinentity（line2）上面的行给了我一个警告'表达式不会产生值'。我理解的是joinentity函数返回void，所以我不能将它分配给折线类型的pll。但是，我需要编写通过将两行连接到autocad数据库而形成的折线。我该如何实现这一目标？

第二个：每当我构建和调试代码以使用Autocad进行测试时，同一行 pll = line1.joinentity（line2）将生成错误并破坏代码。我试图理解错误信息，但无济于事。它读取

AcdbMgd.dll中出现“Autodesk.AutoCAD.Runtime.Exception”类型的异常，但未在用户代码中处理其他信息：eNotApplicable 如果存在此异常的处理程序，则可以安全地继续该程序。

如何解决这个问题？有人可以解释一下并帮助我吗？

已编辑的代码（但问题仍然存在）：

Imports System
Imports System.Runtime.InteropServices
Imports System.Drawing
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD.ApplicationServices.DocumentExtension
Namespace sweeping
            Public Class Testing
                <CommandMethod("jointwolines")>
                Public Shared Sub jointwolines()


                    Dim line1as polyline
                    Dim line2 As Line

 Dim doc As Document = Application.DocumentManager.MdiActiveDocument
                    Dim db As Database = doc.Database
                    Dim ed As Editor = doc.Editor
                    Dim bt As BlockTable
                    Dim btr As BlockTableRecord

                    Using tr As Transaction = db.TransactionManager.StartTransaction()

                line1 = New Polyline()
                line1.AddVertexAt(0, New Point2d(0, 0), 0, 0, 0)
                line1.AddVertexAt(0, New Point2d(100, 0), 0, 0, 0)
                line1.Elevation = 0
                line2 = New Line(new point3d(0,0,0), new point3d(0,0,100))

               bt = tr.GetObject(db.BlockTableId, OpenMode.ForRead)
               btr = tr.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForWrite)

              btr.AppendEntity(line1)
                line1.JoinEntity(line2)
                tr.AddNewlyCreatedDBObject(line1, True)
                tr.Commit()
            End Using
        End Sub
    End Class
End Namespace

有人能帮助我吗？这令人沮丧:(

Answer 1

JoinEntity不会创建新实体，它会修改调用它的实体。这就是你无法获得回报价值的原因。

如果有共线，可以连接两条线，这不是你的情况。您需要在折线上调用此方法，就像在第二个代码段中一样。

来自Autodesk doc：

Polyline.JoinEntity(ies)要求给定的实体为其他实体，未封闭的折线或Polyline2d，线和/或弧实体，其中分享共同的起点或终点。

但是Polyline是一个2D实体，默认情况下位于WCS的XY平面中，并且您尝试添加一条终点，该终点在此XY平面上方100个单位。您需要使用Polyline3d：

<CommandMethod("JOINTWOLINES")>
Public Shared Sub JoinTwoLines()
  Dim doc As Document = Application.DocumentManager.MdiActiveDocument
  Dim db As Database = doc.Database

  Using tr As Transaction = db.TransactionManager.StartTransaction()
    Dim bt As BlockTable
    bt = tr.GetObject(db.BlockTableId, OpenMode.ForRead)

    Dim btr As BlockTableRecord
    btr = tr.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForWrite)

    Dim pl as Polyline3d
    pl = New Polyline3d(Poly3dType.SimplePoly, _
                         new Point3dCollection(), _
                         False)
    btr.AppendEntity(pl)
    tr.AddNewlyCreatedDBObject(pl, True)

    Dim line1 As Line
    line1 = New Line(New Point3d(0, 0, 0), New Point3d(100, 0, 0))
    btr.AppendEntity(line1)
    tr.AddNewlyCreatedDBObject(line1, True)

    Dim line2 As Line
    line2 = New Line(new Point3d(0, 0, 0), new Point3d(0, 0, 100))
    btr.AppendEntity(line2)
    tr.AddNewlyCreatedDBObject(line2, True)

    pl.JoinEntities(new Entity(){line1, line2})

    tr.Commit()
  End Using
End Sub

还有一件事：不要将变量放在sub的顶部。你不是写Pascal而是编写C＃。 Declare your variables where there are used.

使用vb.net在autocad中连接两行时出错

1 个答案: