How to get Block's Layer name?

[MGOMKD]

Hi,

After searching for a long time on the web, does anyone know how to get the block's layer name?

I iterate through Blocks to get informations but i'm not able to code the source to obtain what i want?

Sample source taken from AutoCAD.NET site:

 Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

            '' Open the Block table for read
            Dim acBlkTbl As BlockTable = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead)

            '' Open the Block table record Model space for read
            Dim acBlkTblRec As BlockTableRecord

            acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), OpenMode.ForRead)

            '' Step through the Block table record
            For Each acObjId As ObjectId In acBlkTblRec
                acDoc.Editor.WriteMessage(vbLf & "DXF name: " & acObjId.ObjectClass().DxfName)
                acDoc.Editor.WriteMessage(vbLf & "ObjectID: " & acObjId.ToString())
                acDoc.Editor.WriteMessage(vbLf & "Handle: " & acObjId.Handle.ToString())
                acDoc.Editor.WriteMessage(vbLf)
            Next

            '' Dispose of the transaction
        End Using

 Maybe use nested transaction to iterate through LayerTableId?

ideas?

[Hallex]

Try this function to get the block name

		Public Shared Function EffectiveName(blkref As BlockReference) As String
			If blkref.IsDynamicBlock Then
				Using obj As BlockTableRecord = DirectCast(blkref.DynamicBlockTableRecord.GetObject(OpenMode.ForRead), BlockTableRecord)
					Return obj.Name
				End Using
			End If
			Return blkref.Name
		End Function

~'J'~

[MGOMKD]

Hi Hallex,

I don't want to get the block's name but the layer's name on which the block is attached!

Thanks a lot.

[Hallex]

Sorry for that

To get a layer you have to cast object as Entity, something like:

          Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

                '' Open the Block table for read 
                Dim acBlkTbl As BlockTable = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead)
                '' Open the Block table record Model space for read
                Dim acBlkTblRec As BlockTableRecord
                acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), OpenMode.ForRead)
                '' Step through the Block table record 
                For Each acObjId As ObjectId In acBlkTblRec
                    Dim ent As Entity = acTrans.GetObject(acObjId, OpenMode.ForRead)
                    acDoc.Editor.WriteMessage(vbLf & "DXF name: " & acObjId.ObjectClass().DxfName)
                    acDoc.Editor.WriteMessage(vbLf & "ObjectID: " & acObjId.ToString())
                    acDoc.Editor.WriteMessage(vbLf & "Handle: " & acObjId.Handle.ToString())
                    acDoc.Editor.WriteMessage(vbLf & "Layer: " & ent.Layer.ToString())
                    acDoc.Editor.WriteMessage(vbLf)
                Next
                ''Dispose of the transaction
            End Using

~'J'~

[MGOMKD]

What the...

It  was so easy that i didn't see it! I'll try this.

You're the fastest and the best Hallex!

See you.

PS: I'm French, so all apollogies to my syntaxe script.

[MGOMKD]

yeah it works!

[Hallex]

Glad to help

Cheers 🙂

~'J'~

[MGOMKD]

Hi Hallex,

How are you? I have a new matter that i cannot solve.

You helped me to find le layer's name of a block.

Now i would like to find property's block (AcadObject: Polyline, Arc....). For instance for each block in a particular layer, iterate through each ones, then showing all properties like length,  boundary closed or opened, width....

'Compte du nombre d'objet(s) dans le calque séléctionné'
                Using acTrans = acDocs.MdiActiveDocument.Database.TransactionManager.StartTransaction()
                    acBlkTbl = acTrans.GetObject(acDocs.MdiActiveDocument.Database.BlockTableId, OpenMode.ForRead)
                    acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), OpenMode.ForRead)

                    For Each acObjId As ObjectId In acBlkTblRec
                        Dim MyEnt As Entity = acTrans.GetObject(acObjId, OpenMode.ForRead)
                        If MyEnt.Layer = LayerVal Then
                            'MsgBox(acObjId.ObjectClass.DxfName)
                            Select Case acObjId.ObjectClass.DxfName

                                '*******'
                                '* ARC *'
                                '*******'
                                Case Is = "ARC"
                                                                        
                                    'LENGTH'
                                    MsgBox (?)

                                Case Is = "CIRCLE"
                                Case Is = "DIMENSION"
                                Case Is = "HATCH"
                                Case Is = "LINE"
                                Case Is = "LWPOLYLINE"
                                Case Is = "MTEXTE"
                                Case Is = "POINT"
                                Case Is = "RAY"
                                Case Is = "REGION"
                                Case Is = "TEXTE"
                                Case Is = "SPLINE"
                                Case Is = "XLINE"
                            End Select
                        End If
                    Next acObjId

                End Using

            End With

 Do you have any ideas?

[MGOMKD]

I think i could find a way through this link!

Through the Interface

[Hallex]

This will get you started, I have no time on complete solution

Change properties for every type what you'll want to retrieve

Here is just a quick example:

        <CommandMethod("getsubentitiesinfo", "GetS", CommandFlags.Modal)> _
        Public Shared Sub explodeRef()
            Dim doc As Document = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument
            Dim db As Database = doc.Database
            Dim ed As Editor = doc.Editor
            Dim info As String = ""
            Dim opts As New PromptEntityOptions(vbLf & "Select block reference")
            opts.SetRejectMessage(vbLf & "Select only type of block reference!")
            opts.AddAllowedClass(GetType(BlockReference), False)

            Dim res As PromptEntityResult = ed.GetEntity(opts)
            If res.Status <> PromptStatus.OK Then Return
            Using tr As Transaction = db.TransactionManager.StartTransaction()
                Dim bref As BlockReference = TryCast(tr.GetObject(res.ObjectId, OpenMode.ForRead), BlockReference)

                Dim expobjs As New DBObjectCollection()
                bref.Explode(expobjs)

                Dim table As BlockTableRecord = DirectCast(tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite), BlockTableRecord)
                For Each obj As DBObject In expobjs
                    If TypeOf obj Is Entity Then
                        Select Case obj.GetRXClass().DxfName
                            Case "LWPOLYLINE"
                                info = ""
                                Dim poly As Polyline = TryCast(obj, Polyline)
                                info = String.Format(vbLf + "Number of points: {0}" + vbLf + "Closed? {1}" + vbLf + "Layer: {2}" + vbLf + "Color: {3}", poly.NumberOfVertices, poly.Closed, poly.Layer, poly.ColorIndex)
                                Autodesk.AutoCAD.ApplicationServices.Application.ShowAlertDialog(info)
                            Case "ARC"
                                info = ""
                                Dim arc As Arc = TryCast(obj, Arc)
                                info = String.Format(vbLf + "Center: {0}" + vbLf + "Start angle: {1}" + vbLf + "End angle: {2}" + vbLf + "Start point{3}" + vbLf + "End point: {4}" + vbLf + "Layer: {5}" + vbLf + "Color: {6}", arc.Center, arc.StartAngle, arc.EndAngle, arc.StartPoint, arc.EndPoint, arc.Layer, arc.ColorIndex)
                                Autodesk.AutoCAD.ApplicationServices.Application.ShowAlertDialog(info)
                                ''ETC..ETC...
                            Case "CIRCLE"
                            Case "DIMENSION"
                            Case "HATCH"
                            Case "LINE"
                            Case "LWPOLYLINE"
                            Case "MTEXT"
                            Case "POINT"
                            Case "RAY"
                            Case "REGION"
                            Case "TEXT"
                            Case "SPLINE"
                            Case "XLINE"

                        End Select

                    End If
                Next

                'clean up memory, optional
                For Each obj As DBObject In expobjs
                    obj.Dispose()
                Next
                tr.Commit()

            End Using

        End Sub

~'J'~

[MGOMKD]

Hi Hallex,

I'm very surprised you're very quick! Thank you.

Now i have to understand code and work on it.

See you!

[Hallex]

Good to hear that,

Just a hint, you could be able to collect all of values of the particular subentity

into the

 List(Of (List (Of String))

( every single item inside into the List (of String)),

then this would be easier to write to the data file on another storage,

hth,

~'J'~

[MGOMKD]

Hi Hallex, how are you?

I try de write the best code to obtain what i want but when i run it on AutoCAD, i have a dialog box error.

So in a module vars.

Module Paramètres

    '********************************'
    '* Paramètres du Document Actif *'
    '********************************'

    Public acDocs As DocumentCollection = Application.DocumentManager
    Public acDoc As Document = acDocs.MdiActiveDocument
    Public acCurDb As Database = acDoc.Database
    Public acTrans As Transaction
    Public acBlkTbl As BlockTable
    Public acBlkTblRec As BlockTableRecord
    
End Module

 And the code

Sub ExcelApp(ByVal LayerVal)

        '***********************'
        '* Génération du fichier Excel *'
        '***********************'

Using acTrans = acCurDb.TransactionManager.StartTransaction()
    acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead)
    acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), OpenMode.ForRead)
                    
    For Each acObjId As ObjectId In acBlkTblRec
          Dim MyEnt As Entity = acTrans.GetObject(acObjId, OpenMode.ForRead)
          If MyEnt.Layer = LayerVal Then

               Select Case acObjId.ObjectClass.DxfName

                      '******'
                      '* ARC *'
                      '******'
                     Case Is = "ARC"
                     Dim MyArc As AcadArc = CType(acTrans.GetObject(MyEnt.AcadObject, OpenMode.ForRead), AcadArc)
                     MsgBox(MyArc.ArcLength)

         End If
    Next acObjId
End Using

                                    

 Error message: Impossible to cast type's object.

                          'Autodesk.AutoCAD.DatabaseServices.Arc' to 'Autodesk.AutoCAD.Interop.Common.AcadArc'

Am i on the right way?

[MGOMKD]

Hi all,

I just found what's wrong in my source code!

Change these lines:

Dim MyArc As AcadArc = CType(acTrans.GetObject(MyEnt.AcadObject, OpenMode.ForRead), AcadArc)
                     MsgBox(MyArc.ArcLength)

 by:

Dim MyArc As Autodesk.AutoCAD.DatabaseServices.Arc = TryCast(MyEnt, Entity)
MsgBox (MyArc.Length)

 Thanks to Hallex!

[Hallex]

Glad you solved it by yourself,

Happy coding

~'J'~

[MGOMKD]

Hi,

I've met another matter!

When I iterate through specifics entities (like LWPOLYLINE, LINE, CIRCLE,...etc) sometimes my source code deal with "POINT". So I would like to cast it to obtain coordinates (X, Y, Z).

Dim MyPoint As Point3d = TryCast(MyEnt, Entity)

But the matter is I cannot access coordinate of these entity, cause Point3d belongs to Autodesk.AutoCAD.Geometry whereas MyEnt belong to AutoDesk.AutoCAD.DatabaseServices

How could I reach these informations?

[Hallex]

You could be able to get coordinates from polyline

with help of these functions:

''============================= LWPolyline =======================
 Public Shared Function getAllVertices(ByVal ent As Polyline) As Point2dCollection

    Dim verCollection As Point2dCollection = New Point2dCollection()
    Dim vertex As Point2d
    Dim i As Integer = 0
      For i = 0 To ent.NumberOfVertices - 1    
        vertex = ent.GetPoint2dAt(i)       
     verCollection.Add(vertex)    
    Next    
    Return verCollection  
  End Function
''============================= 3dPoly =======================
     Public Shared Function Get3dPolyVertices(ByVal poly3d As Polyline3d) As Point3dCollection  
            Dim pts As New Point3dCollection
            For i As Integer = 0 To poly3d.EndParam
                pts.Add(poly3d.GetPointAtParameter(i))
            Next i
        Return pts
    End Function

 From line you can get coordinates:

Dim sp as point3d= line.StartPoint

dim ep as point3d= line.EndPoint

same way for arc,circle etc

just find in Intellisence box appropriate properties for them all

~'J'~

[MGOMKD]

Hi Hallex!

Always at the top!

I work on it, thanks a lot.

[Hallex]

:Glad to help

Cheers :smileyhappy

~'J'~

[MGOMKD]

Hi Hallex,

I had found another way to obtain coords.

Case Is = "POINT"

                                    '*********'
                                    '* POINT *'
                                    '*********'
                               
                                    'Insertion du texte'
                                    acMText = New MText()
                                    Dim X as Double = MyEnt.GeometricExtents.MinPoint.X
                                    Dim Y as Double = MyEnt.GeometricExtents.MinPoint.Y
                                    Dim Z as Double = MyEnt.GeometricExtents.MinPoint.Z

                                    With acMText
                                        acMText.SetDatabaseDefaults()
                                        acMText.Location = New Point3d(X, Y, Z)
                                        acMText.Attachment = AttachmentPoint.BottomLeft
                                        acMText.TextHeight = acHeightText
                                        acMText.Contents = i
                                    End With

                                    acBlkTblRec.AppendEntity(acMText)
                                    acTrans.AddNewlyCreatedDBObject(acMText, True)

                                    'Libération de la variable'
                                    MyEnt = Nothing
                                    acMText = Nothing

 But what the difference between "MinPoint" and "MaxPoint"? I tried twice and it gaves the same result!

Thank You.