.NET

[#1]

Hello All,

I have created a jig to create a jig for road design that floats a grade from a vertical curve. The user selects an existing curve and then the jigs calculates the tangent point on this curve and rubber bands a line to it.

The Jig is a class called clsFloatPtJig.
The jig gets called from a class called clsVerticalAlignment.

All works well for about the first five seconds and then suddenly the rubber band and text disappears and then when the user clicks a point, AutoCAD crashes. At this point I get various errors including 'Exception attempted to read or write to protected memory.'

I have taken all of my fancy calls out of my jig, so it is reduced to just a rubber band, and it still crashes. This has lead me to belive that the problem must be elsewhere.

The only thing that I think could possibly cause this is perhaps .NET is Garbage collecting the VerticalAlignment class for some reason, thereby shutting down jig.


Here is the Jig code:

Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD
Public Class clsFloatPointJig
Inherits DrawJig
Dim BasePt As Point3d
Dim myPr As PromptPointResult
Dim TextStyle As New Autodesk.AutoCAD.GraphicsInterface.TextStyle("arial.ttf", "", 3.5, 1, 0, 0, False, False, False, False, False, "AA")
Dim _Vertical As clsVerticalAlignment
Dim Sol As clsVerticalAlignment.VCSolution
Dim pt1(2) As Double
Dim pt2 As New Point3d(100, 100, 0)
Dim _eKey As String
Dim _IsAfter As Boolean
Dim Vec1 As New Vector3d(0, 1, 0)
Public Sub New(ByVal eKey As String, ByVal IsAfter As Boolean, ByVal VA As clsVerticalAlignment)

_eKey = eKey
_IsAfter = IsAfter
_Vertical = VA
End Sub
Function startJig() As PromptPointResult
Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor

Try
myPr = ed.Drag(Me)
Do
Select Case myPr.Status
Case PromptStatus.OK
Return myPr
Exit Do
End Select
Loop While myPr.Status <> PromptStatus.Cancel
Return myPr
Catch ex As Exception
MsgBox("Exception" & ex.Message)
End Try
End Function
Protected Overrides Function Sampler(ByVal prompts As JigPrompts) As SamplerStatus

Try
Dim JigOpts As New JigPromptPointOptions
JigOpts.Message = vbCrLf & "Select TP point: "
JigOpts.UserInputControls = UserInputControls.NoZeroResponseAccepted
myPr = prompts.AcquirePoint(JigOpts)
If myPr.Value.IsEqualTo(BasePt) Then
Return SamplerStatus.NoChange
Else
BasePt = myPr.Value
pt1(0) = _Vertical.X2Chainage(BasePt.X)
pt1(1) = _Vertical.Z2Level(BasePt.Y)
Sol = _Vertical.GradeThroughPoint(pt1, _IsAfter, _eKey)
pt2 = New Point3d(_Vertical.Chainage2X(Sol.Solution1.Chainage), _
_Vertical.Level2Z(Sol.Solution1.Level), 0)
End If
Return SamplerStatus.OK
Catch ex As Exception
MsgBox("Exception" & ex.Message)
End Try
End Function
Protected Overrides Function worlddraw(ByVal Draw As _
Autodesk.AutoCAD.GraphicsInterface.WorldDraw) As Boolean

Try
If Sol.Solutions = 1 Then
Draw.Geometry.WorldLine(pt2, BasePt)
Draw.Geometry.Text(pt2, Geometry.Vector3d.ZAxis, _
Vec1, "CH " & FormatNumber(Sol.Solution1.Chainage, 3) & ", Lvl " & FormatNumber(Sol.Solution1.Level, 3), False, TextStyle)
Draw.Geometry.Text(BasePt, Geometry.Vector3d.ZAxis, _
Vec1, "CH " & FormatNumber(pt1(0), 3) & ", Lvl " & FormatNumber(pt1(1), 3), False, TextStyle)
End If
Catch ex As Exception
MsgBox("Exception" & ex.Message)
Return False
End Try
Return True
End Function
End Class

And here is the calling code from the VerticalAlignment class


Public Sub FloatPoint(ByVal eKey As String, ByVal IsAfter As Boolean)
Dim SelPt As Autodesk.AutoCAD.EditorInput.PromptPointResult
Dim myJig As New clsFloatPointJig(eKey, IsAfter, Me)

SelPt = myJig.startJig()
If Not IsNothing(SelPt) Then
MsgBox(SelPt.ToString)
End If
End Sub

I am testing this class by creating a new instance of a vertical alignment and then calling the FloatPoint function.

Is this scenario described above possible and if so are there any strategies I can employ to avoid this.

Regards

Martin Duke

[#2]

Put the try after the do