Topic: eInvalidInput when trying to offset Polyline2d

[Proctor]

Hello: I'm working w/ the curves class - offsetting polylines and inserting blocks along the offset curves. This works great for simple polys; however, when i try to run it on a polyline2d type, it bombs on the following line:

Code: [Select]

Dim pt As Point3d = newPl.GetPointAtDist((12 / num) * z)
Here's the code I'm running that leads up to it:

Code: [Select]

Sub OffsetMyPoly(ByVal pEstimatePolyId, ByVal dDouble)
        Try
            Dim ed As Editor = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.Editor
            Dim num As Double = iModulesPerUnit 'this number represents the distance between the leds given the product chosen
            Dim doc As Document = Application.DocumentManager.MdiActiveDocument
            Dim db As Database = doc.Database

            Using trans As Transaction = ed.Document.TransactionManager.StartTransaction()
                Dim ent As Entity = DirectCast(trans.GetObject(pEstimatePolyId, Autodesk.AutoCAD.DatabaseServices.OpenMode.ForRead), Entity)
              [color=red]'Was using this line and changed it to the line below it.
                Dim pl As Polyline = DirectCast(ent, Polyline) [/color]
                [color=red]Dim pl As Polyline2d = DirectCast(ent, Polyline2d)[/color]

                Dim curves As DBObjectCollection = pl.GetOffsetCurves(-dDouble)
                Dim bt As BlockTable = doc.Database.BlockTableId.GetObject(Autodesk.AutoCAD.DatabaseServices.OpenMode.ForRead)
                Dim btr As BlockTableRecord = bt(BlockTableRecord.ModelSpace).GetObject(Autodesk.AutoCAD.DatabaseServices.OpenMode.ForWrite)
                Dim blkdef As BlockTableRecord = bt(sBlockName).GetObject(Autodesk.AutoCAD.DatabaseServices.OpenMode.ForRead)

                For i As Integer = 0 To curves.Count - 1
                   [color=red]'Was using this line and changed it to the line below it
                     Dim newPl As Polyline = DirectCast(curves.Item(i), Polyline)[/color]
                   [color=red] Dim newPl As Polyline2d = DirectCast(curves.Item(i), Polyline2d)[/color]
                    'GET LENGTH OF NEW POLY
                    Dim length As Double = newPl.Length
                    'use the length of the poly chosen to tell us how many leds(blocks) to insert
                    Dim noOfLeds As Integer = CInt((length / 12) * num)
                    'MEASURE
                    For z As Integer = 0 To noOfLeds - 1
                       [color=red] 'bombs on this line:
                        Dim pt As Point3d = newPl.GetPointAtDist((12 / num) * z)[/color]                       
                        Dim endPoint As Point3d = newPl.GetPointAtDist(((12 / num) * z) + 0.1)
                        Dim v As Vector3d = endPoint - pt
                        Dim plane As New Plane(New Point3d(0, 0, 0), New Vector3d(0, 0, 1))
                        Dim ang As Double = v.AngleOnPlane(plane)
                        Dim blkref As New BlockReference(pt, bt(sBlockName))
                        btr.AppendEntity(blkref)
                        blkref.Rotation = ang
                        trans.AddNewlyCreatedDBObject(blkref, True)
                    Next
                    ed.Regen()
                    trans.Commit()
                    '/MEASURE
                Next
                curves.Dispose()

            End Using
        Catch ex As Autodesk.AutoCAD.Runtime.Exception
            MsgBox(ex.Message)
        Finally
            'trans.Dispose()
        End Try
    End Sub
Does anyone have any idea what I'm doing wrong?

Thanks for your help,
Proctor

[Jeff_M]

Hi Proctor,
I believe that you must add the newly offset pline to a block (ModelSpace being a block) before you can query for the point. This allowed the code to run without failing (I did comment out irrelevant portions):

Code: [Select]

                    Dim newPl As Polyline2d = DirectCast(curves.Item(i), Polyline2d)
                    btr.AppendEntity(newPl)
but the Offset pline was not in the drawing still. Changing it to this did so....

Code: [Select]

                    Dim newPl As Polyline2d = DirectCast(curves.Item(i), Polyline2d)
                    btr.AppendEntity(newPl)
                    trans.AddNewlyCreatedDBObject(newPl, True)
If this worked on LWPlines, did you have similar code that was skipped over in creating this one for the 2d plines?

[Proctor]

Boy...do I have a lot to learn. That makes sense...and it's working now!!! Thank you so much.

I'm not sure why it was working for the LWPline? I didn't create the new poly in modelspace ....

Anyway, thanks again for your help!!!
Proctor