Use AutoCAD API in DWG file

By Adam Nagy

When interacting with a DWG type drawing document, you can also use the AutoCADAPI in it through the ObjectDBX type library.

From the DrawingDocument.ContainingDWGDocument you'll get back an AcadDatabase object that you can use to drill down into the drawing's contents.

As an example for showing how to achieve something using the Inventor API vs the AutoCAD API, here are two functions which are supposed to be doing the same thing: iterating through the Sheets (Layouts in AutoCAD) and set the Prompt Text values (Attribute Text in AutoCAD) for a given AutoCADBlock (Block Reference in AutoCAD).

Inventor code:

Sub SetAttributesOnSheets()

  Dim oDrawDoc As DrawingDocument
  Set oDrawDoc = ThisApplication.ActiveDocument
    
  Dim Blockname As String
  Blockname = "Testblock"

  Dim oSheet As Sheet
  For Each oSheet In oDrawDoc.Sheets
    Dim oBlock As AutoCADBlock
    For Each oBlock In oSheet.AutoCADBlocks
      If oBlock.Name = Blockname Then
        Dim tagStrings() As String
        Dim textStrings() As String
    
        oBlock.GetPromptTextValues tagStrings, textStrings
    
        Dim i As Integer
        For i = LBound(tagStrings) To UBound(tagStrings)
          If tagStrings(i) = "TEXT1" Then
            textStrings(i) = "text1text"
          ElseIf tagStrings(i) = "TEXT2" Then
            textStrings(i) = "text2text"
          End If
        Next' If multiple tag strings are the same then it will' only set the value for the first one of them' That's one of the reasons for this article' to show how to do it using the AutoCAD API instead' which seems to be working fine and can be used as' a workaround
        oBlock.SetPromptTextValues tagStrings, textStrings
      End If
    Next
  Next
End Sub

AutoCAD/ObjectDBX code: 

Sub SetAttributesOnLayouts()

  Dim oDrawDoc As DrawingDocument
  Set oDrawDoc = ThisApplication.ActiveDocument
   
  Dim Blockname As String
  Blockname = "Testblock"' Using AutoCAD API' If you want to declare variables using their' exact type, which will provide you with intelli-sense' as well, then you need to reference the' "AutoCAD/ObjectDBX Common  Type Library"' through "Tools >> References"' You can also declare the variables as "Object" instead, in' which case you are doing so called "late-binding"' which does not require you to reference the type library:' e.g.: Dim oDb As Object
  Dim oDb As AcadDatabase
  Set oDb = oDrawDoc.ContainingDWGDocument' This way we can set the attribute values even inside ' the model space layout which does not seem to be ' possible even through the Inventor User Interface 
  Dim oLayout As AcadLayout
  For Each oLayout In oDb.Layouts
    Dim oBlock As AcadBlock
    Set oBlock = oLayout.Block
    Dim oEnt As AcadEntity
    For Each oEnt In oBlock
      If TypeOf oEnt Is AcadBlockReference Then
        Dim oBR As AcadBlockReference
        Set oBR = oEnt
        If oBR.Name = Blockname Then
          Dim oAtts As Variant
          oAtts = oBR.GetAttributes()
          Dim i As Integer
          For i = LBound(oAtts) To UBound(oAtts)
            Dim oRef As AcadAttributeReference
            Set oRef = oAtts(i)
            If oRef.TagString = "TEXT1" Then
              oRef.TextString = "text1text"
            ElseIf oRef.TagString = "TEXT2" Then
              oRef.TextString = "text2text"
            End If
          Next
        End If
      End If
    Next
  Next
  Call oDrawDoc.Update
End Sub

Result: