Lisp Variable from AutoCAD Electrical with Invoke

[Anonymous]

Hi,

I'm having struggling with 2 items

1. When running the following code it doesn't return the value into "SCRATCH_FNAM"

2. How can I read back this variable? a example would be wonderfull because I'm a newbie in Vb.net

If I remove the following line it seems to work

 resBuf.Add(New TypedValue(Lisp_AE.RTSTR, "scratch_fnam"))

but I need to have the projectlocation from AutoCAD electrical. They provide the following API

    (setq fnam (c:wd_mdb_get_proj_scratch_dbnam nil)) ; "nil"=get current proj mdb file name

to get the value Scratch_fnam I tried:

dim Rbin as resultbuffer = Invoke(resbuf)

but how further????

Vb.Net code:

Imports System
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.EditorInput
Imports System.Runtime.InteropServices
Imports Autodesk.AutoCAD.ApplicationServices.Application
Imports Autodesk.AutoCAD.Geometry
Public Class Lisp_AE

    Public Const RTREAL As Int32 = 5001
    Public Const RTSHORT As Int32 = 5003
    Public Const RTSTR As Int32 = 5005
    Public Const RTLONG As Int32 = 5010
    Public Const RTENAME As Int32 = 5006

    ' Import the acedInvoke function definition
    Private Declare Function acedInvoke Lib "acad.exe" (ByVal args As IntPtr, ByRef result As IntPtr) As Integer

    '''//////////////////////////////////////////////////////////////////
    ' Function: InvokeLispFunc
    ' Description: This function calls the acedInvoke function.
    ' Parameters: args - Data structure containing the Lisp function name and arguments to be passed into the function
    '             stat - An int to store function execution status code
    ' Return Value: returns from lisp if successful, otherwise, return null
    '''//////////////////////////////////////////////////////////////////
    Public Shared Function InvokeLispFunc(ByVal args As ResultBuffer, ByRef stat As Integer) As ResultBuffer
        Dim rb As IntPtr = IntPtr.Zero
        stat = acedInvoke(args.UnmanagedObject, rb)
        If (stat = CType(PromptStatus.OK, Integer)) Then
            Return CType(Autodesk.AutoCAD.Runtime.DisposableWrapper.Create(GetType(ResultBuffer), rb, True), ResultBuffer)
        End If
        Return Nothing
    End Function
End Class

Public Class SampleMainClass
   Public Shared Function ProjPath() As Boolean

        Dim stat As Integer = 0
        Dim bOK As Boolean = True
        Dim resBuf As ResultBuffer = New ResultBuffer
        resBuf.Add(New TypedValue(Lisp_AE.RTSTR, "scratch_fnam"))
        resBuf.Add(New TypedValue(Lisp_AE.RTSTR, "c:wd_mdb_get_proj_scratch_dbnam"))
        resBuf.Add(New TypedValue(Lisp_AE.RTSTR, "nil"))

        Dim ret As ResultBuffer = Lisp_AE.InvokeLispFunc(resBuf, stat)
        If (ret Is Nothing) Then
            Return False
        End If
        Dim rbChain() As TypedValue = ret.AsArray
        If (rbChain.Length = 0) Then
            bOK = False
        End If
        Return bOK
    End Function
End Class

Thanks in advance for your help.

[Anonymous · Accepted solution]

In order to get/set lisp variable You can use pair of functions acedGetSym / acedPutSym 

http://forums.autodesk.com/t5/NET/acedGetSym-and-acedPutSym-in-NET-applications/m-p/1635754#M3409

[Anonymous]

Thanks for your help.

Didn't see the forest for the tree's yesterday.

Your link helped me to do the trick