[V8i SELECTseries 3 VBA], Cannot define a levels object with ActiveDesignFile.Levels

Hi Etienne,

what exactly do you want to achieve?

To iterate levels is rarely useful and other ways can be used (but it requires to know what your aim is).

With regards,

  Jan

One more comment:

It's not recommended to use "index" to access levels, because it's just a position of level in a list, starting from 1 ... which is the reason why your code crashes.

As written in MicroStation VBA help, when you really need to iterate all levels, use foreach loop.

With regards,

  Jan

Etienne Duperey said:

I am having trouble with this code

 For i = 0 To UBound(OptionVB_CadreDecoupe)

A perennial problem with VBA is array indices: do they start at 0 or 1?  Does an array end at N or N-1?  See the Option Base { 0 | 1 } directive.

ReDim elLevel(UBound(OptionVB_CadreDecoupe))

Your ReDim statement by default sets the lower bound of the array to the current Option Base value.

You are attempting to get a level whose name is CADRE_A3.  Does that level exist?

Jan Šlegr said:

when you really need to iterate all levels, use foreach loop

Follow Jan's advice.  If you look at VBA help, it does not recommend indexing levels with an integer, but with the level name: Levels supports the standard collection interface, so it is possible to step through the collection using the For Each statement. It is also possible to retrieve a Level by indexing into the Levels collection with the level's name.

Dim oFurnitureLevel As Level
Set oFurnitureLevel = ActiveDesignFile.Levels("Furniture")

Hi Jan,

I try to retrieve a list of element according to the level, in order to know for example their position, their length or for example if an element of level 1 intersects with an element of level 2.

Etienne Duperey said:

I try to retrieve a list of element according to the level

In such case, why to iterate all levels in active DGN file?

Etienne Duperey said:

if an element of level 1 intersects with an element of level 2.

It's about to obtain level object(s) based on their name(s). No iteration of all levels is necessary.

Regards,

  Jan

Hi Jon,

the index starts at 0 and ends at N-1.

yes the CADRE_A3 does exist, but not in the active Dgn, the latter is in a Dgn referenced in the active Dgn.

I do not understand the rest, I do not want to index a level with an integer but by its name.
I will take a closer look at the documentation on this subject.

If in doubt I will add the end of my function :

    Set elScanCriteria = New ElementScanCriteria
    elScanCriteria.ExcludeAllLevels                         'Défini les critéres
    
    For i = 0 To UBound(elLevel)
        elScanCriteria.IncludeLevel elLevel(i)              'du scan a faire
    Next
    
    Set elEnum = ActiveModelReference.Scan(elScanCriteria)
    
    Do While elEnum.MoveNext
        res = GetLinkedElement(elEnum.Current)
    Loop

    If ops = "ID" Then
        
    
    End If

        GetFolio = elEnum.Clone.BuildArrayFromContents            'Renvoie un tableau du résultat

End Function

Etienne Duperey said:

yes the CADRE_A3 does exist, but not in the active Dgn, the latter is in a Dgn referenced in the active Dgn.

If you want to access elements in a reference, it's not possible to use ActiveModelReference.Scan, but to scan proper ModelReference.

Etienne Duperey said:

I do not want to index a level with an integer but by its name.

In such case, just access existing level list using the level name. But be aware you have to use the right ModelReference.

Etienne Duperey said:

If in doubt I will add the end of my function :

I see several problems in the code you shared (but it's not complete, so maybe I am wrong):

• To iterate and add levels in this way will probably not work.
• If element / level is in reference and not in active model, it will not work (the scanning has to be applied to the right model, not the active one).
• To use BuildArrayFromContents is generally wrong and leads to big memory consumption. Probably never it's mandatory to build the array and everything can be done during Do While loop.

Etienne Duperey said:

I will take a closer look at the documentation on this subject.

You really should to do it. There are plenty of code snippets available in MicroStation VBA help, and also some mvba examples (files) are delivered with MicroStation installation.

Regards,

  Jan

Etienne Duperey said:

I try to retrieve a list of element according to the level

Etienne Duperey said:

the CADRE_A3 does exist, but not in the active Dgn, the latter is in a Dgn referenced

If you want to build a list of lines on a particular level in all reference attachments, then you need to enumerate those models.  In each model, search for lines on that level.

Write a function that creates your scan criteria for a model...

Function ScanCriteriaForLinesOnLevel (ByVal levelName As String, ByVal oModel As ModelReference) As ScanCriteria
    Dim oLevel As Level
    Set oLevel = oModel.Levels (levelName)
    If oLevel Is Nothing Then
      Debug.Print "Level '" & levelName & "' does not exist in model '" & oModel.Name & "'"
      Exit Function
    End If
    
    Dim oCriteria As New ElementScanCriteria
    oCriteria.ExcludeAllLevels
    oCriteria.IncludeLevel oLevel
    oCriteria.ExcludeAllTypes
    oCriteria.IncludeType msdElementTypeLine
    oCriteria.IncludeType msdElementTypeLineString
    
    Set ScanCriteriaForLinesOnLevel = oCriteria
End Function

Now get a list of lines from a model...

Function GetLinesOnLevel (ByVal levelName As String, ByVal oModel As ModelReference) As Element()
    Dim oLines As ElementEnumerator
    Set oLines = oModel.Scan (ScanCriteriaForLinesOnLevel (levelName, oModel)
    GetLinesOnLevel = oLines.BuildArrayFromContents()
End Function

Now enumerate the active model and its attachments...

Dim oLines() As Element
oLines = GetLinesOnLevel (levelName, ActiveModelReference)
Dim oModel As ModelRefernce
For Each oModel In ActiveModelReference.Attachments
  oLines = GetLinesOnLevel (levelName, oModel)
Next oModel