Passinga Structure to a Sub

[mgorecki]

Hello, I have a need to save coordinates points for a couple of objects, so I decided to use a structure object.

Here is my structure for an 8 sided polygon:

 Structure OctoPolygon
        Public Shared pt1 As New Geometry.Point3d
        Public Shared pt2 As New Geometry.Point3d
        Public Shared pt3 As New Geometry.Point3d
        Public Shared pt4 As New Geometry.Point3d
        Public Shared pt5 As New Geometry.Point3d
        Public Shared pt6 As New Geometry.Point3d
        Public Shared pt7 As New Geometry.Point3d
        Public Shared pt8 As New Geometry.Point3d

        Public Sub setPoints(ByVal drawingStartPoint As Double, ByVal mcSize As Double, ByVal mcCenter2Cham As Double)
            Dim mcX1neg As Double, mcX2neg As Double, mcX1pos As Double, mcX2pos As Double
            Dim mcY1neg As Double, mcY2neg As Double, mcY1pos As Double, mcY2pos As Double
            Dim mcChamLength As Double

            ' Set the moldcap chamfer value
            mcChamLength = ((mcSize / 2) - mcCenter2Cham)

            ' Set the new corners based on length and chamfer of the polygon
            mcX1neg = drawingStartPoint - (mcSize / 2)
            mcX2neg = drawingStartPoint - ((mcSize / 2) - mcChamLength)
            mcX1pos = drawingStartPoint + (mcSize / 2)
            mcX2pos = drawingStartPoint + ((mcSize / 2) - mcChamLength)
            mcY1neg = ((mcSize / 2) * -1)
            mcY2neg = (((mcSize / 2) - mcChamLength) * -1)
            mcY1pos = (mcSize / 2)
            mcY2pos = ((mcSize / 2) - mcChamLength)

            pt1 = New Geometry.Point3d(mcX1neg, mcY2neg, 0)
            pt2 = New Geometry.Point3d(mcX2neg, mcY1neg, 0)
            pt3 = New Geometry.Point3d(mcX2pos, mcY1neg, 0)
            pt4 = New Geometry.Point3d(mcX1pos, mcY2neg, 0)
            pt5 = New Geometry.Point3d(mcX1pos, mcY2pos, 0)
            pt6 = New Geometry.Point3d(mcX2pos, mcY1pos, 0)
            pt7 = New Geometry.Point3d(mcX2neg, mcY1pos, 0)
            pt8 = New Geometry.Point3d(mcX1neg, mcY2pos, 0)
        End Sub

    End Structure

Then I want to send that object to a sub that will draw the octagonal polyline:

' Create octagonal moldcap shapes
    Public Sub addPolyOctagon(ByVal polyStruct As OctoPolygon)
        Dim podPolyOctagonTransMan As DatabaseServices.TransactionManager
        Dim podPolyOctagonTrans As DatabaseServices.Transaction
        Dim podDWG As ApplicationServices.Document
        Dim podBT As DatabaseServices.BlockTable
        Dim podBTR As DatabaseServices.BlockTableRecord

        ' Get the active document and begin a Transaction
        podDWG = ApplicationServices.Application.DocumentManager.MdiActiveDocument
        podPolyOctagonTransMan = podDWG.TransactionManager
        podPolyOctagonTrans = podPolyOctagonTransMan.StartTransaction

        ' Open the BlockTable for Read
        podBT = podDWG.Database.BlockTableId.GetObject(DatabaseServices.OpenMode.ForRead)
        podBTR = podBT(DatabaseServices.BlockTableRecord.ModelSpace).GetObject(DatabaseServices.OpenMode.ForWrite)

        ' Draw the polyline
        Dim polyCorners As New Autodesk.AutoCAD.Geometry.Point3dCollection
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt1))
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt2))
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt3))
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt4))
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt5))
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt6))
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt7))
        polyCorners.Add(New Geometry.Point3d(polyStruct.pt8))
        Dim mcPLine As New DatabaseServices.Polyline2d(DatabaseServices.Poly2dType.SimplePoly, _
        polyCorners, 0, True, 0, 0, Nothing)
        podBTR.AppendEntity(mcPLine)
        podPolyOctagonTrans.AddNewlyCreatedDBObject(mcPLine, True)

        ' Commit the Transaction
        podPolyOctagonTrans.Commit()
        podPolyOctagonTrans.Dispose()
        podPolyOctagonTransMan.Dispose()

    End Sub

 It's having a real problem with the lines:

polyCorners.Add(New Geometry.Point3d(polyStruct.pt1))

It says "Access of shared member, constant member, enum member, or nested type through an instance; qualifying expression wil not be evaluated"

Can someone please explain the to me, and tell me how I can get the sub to see the points defined in the structure?

Thanks,

Mark

[norman.yuan]

Remove "Shared" from the structure's public member declaration.

I do not know the exact reason(s) why you want to expose the 8 Point3d member as "Shared". At least, according to the code you showed here and to what you described for your need, they should not be "Shared" members, assuming before the sub addPolyOctagon() is called, you have instantiated the structure and called its method setPoints() and then passed it to the addPolyOctagon().

[mgorecki]

Hi Norman, thank you for replying.  I guess I used "Shared" ot of ignorance.  I saw structure code somewhere and copied its format.

Ok, so now I removed the "Shared" from the structure:

 Structure OctoPolygon
        Public pt1 As Geometry.Point3d
        Public pt2 As Geometry.Point3d

But the lines like:

polyCorners.Add(New Geometry.Point3d(polyStruct.pt1))

now have this issue:

"Value of type 'Autodesk.AutoCAD.Geometry.Point3d' cannot be converted to '1-dimensional array of Double'.

I thought it just needed a point and those are 3d points.

[mgorecki]

Ok So I changed the line to be:

polyCorners.Add(polyStruct.pt1)

It seems to accept that.

[hgasty1001]

Hi,

Try : polyCorners.Add(polyStruct.pt1)

Gaston Nunez

[DiningPhilosopher]

Using a struct in the case you show, to store only multiple instances of a single type, is really inappropriate.

You can use an array of Point3d or a Point3d collection, and reference the elements via their index, which is what your structure members (pt1-pt7) are.

If per chance, you have other types of data that you want to also include, you can use a struct for something like that, but the Point3d members should still not be there, because the struct can contain an array of Point3d or Point3dCollection as well.