topic Re: Xrefs Loaded or Unloaded in VBA Forum

Xrefs Loaded or Unloaded

Anonymous — Fri, 10 May 2002 06:36:26 GMT

Need an example in VBA of checking to see if Xrefs are Loaded or Unloaded.

I can't seem to find anything for this.

Chris Payne

Re: Xrefs Loaded or Unloaded

Anonymous — Fri, 10 May 2002 09:26:50 GMT

If the XREf is not resolved (unloaded or not found),
then attempting to reference the XRefDatabase property
of the corresponding Block object for the Xref will
raise an error with the description "No database"

"Paynec" wrote in message
news:f0dcb33.-1@WebX.maYIadrTaRb...
> Need an example in VBA of checking to see if Xrefs are Loaded or Unloaded.
> I can't seem to find anything for this.
>
> Chris Payne
>
>

Re:

Anonymous — Fri, 10 May 2002 10:35:47 GMT

Thanks, Tony, I think that will fill my needs.

Mike Weaver

"Tony Tanzillo" wrote in message
news:D2830174F828C8559BF56BEC9953DACF@in.WebX.maYIadrTaRb...
> If the XREf is not resolved (unloaded or not found),
> then attempting to reference the XRefDatabase property
> of the corresponding Block object for the Xref will
> raise an error with the description "No database"
>
>
> "Paynec" wrote in message
> news:f0dcb33.-1@WebX.maYIadrTaRb...
> > Need an example in VBA of checking to see if Xrefs are Loaded or
Unloaded.
> > I can't seem to find anything for this.
> >
> > Chris Payne
> >
> >
>
>
>
>

Re:

Ed__Jobe — Fri, 10 May 2002 10:54:21 GMT

How's this Tony?

Public Function IsXrefResolved(xref As AcadExternalReference) As Boolean
'If the XREf is not resolved (unloaded or not found),
'then attempting to reference the XRefDatabase property
'of the corresponding Block object for the Xref will
'raise an error with the description "No database".
On Error GoTo ErrHandler
Dim objBlock As AcadBlock
Dim cnt As Integer

Set objBlock = ThisDrawing.Blocks(xref.Name)
If objBlock.IsXRef = True Then
'this is just to access the db,
'an error will occur if not loaded
cnt = objBlock.XRefDatabase.Blocks.Count
IsXrefResolved = True
Else
IsXrefResolved = False
End If
Exit Function

ErrHandler:
If Err.Number = -2145386390 Then
IsXrefResolved = False
Else
MsgBox Err.Number & vbCrLf & Err.Description, vbCritical, "function IsXrefResolved"
End If
End Function

-Ed

Re:

Anonymous — Fri, 10 May 2002 11:39:02 GMT

That's fine but there are a few rules that
you should follow when writing 'generic" or
modular code that is designed to be resuable
in many scenarios.

The most important thing is that you avoid
binding your code to the Active document, vis
a vis the use of 'ThisDrawing'.

In this particular case, you're passing in an
AcadExternalReference to your function, but
you are using the ThisDrawing variable to get
the corresponding block. This is wrong, and
impedes code modularity (not to mention the
fact that you are making the assumption that
the XRef is in the ActiveDocument).

What if the XRef isn't in the ActiveDocument?

What if it's in an AxDbDocument, or another
document open in the editor (in this case, I
don't think an AcadExternalReference would
appear in an AxDbDocument, but the general
concept I'm trying to convey here applies to any
type of AcadEntity that you would pass into a
modular function or sub).

So, consider modifying the code thusly:

Public Function IsResolved(XRef As AcadExternalReference) As Boolean
On Error Goto Catch
Dim objBlock As AcadBlock

' Pay attention to the next line, it avoids
' using ThisDrawing, and gets the document
' from the XRef parameter:

Set objBlock = XRef.Document.Blocks(XRef.Name)

objBlock.XRefDatabase.Blocks
IsResolved = True
Exit Sub
Catch:
IsResolved = False
End Function

With this change, you can now use this code on any
AcadExternalReference because the code correctly
avoids binding to the active document in the AutoCAD
editor.

"Ed_Jobe" wrote in message news:f0dcb33.5@WebX.maYIadrTaRb...
> How's this Tony?
> Public Function IsXrefResolved(xref As AcadExternalReference) As Boolean
> 'If the XREf is not resolved (unloaded or not found),
> 'then attempting to reference the XRefDatabase property
> 'of the corresponding Block object for the Xref will
> 'raise an error with the description "No database".
> On Error GoTo ErrHandler
> Dim objBlock As AcadBlock
> Dim cnt As Integer
>
> Set objBlock = ThisDrawing.Blocks(xref.Name)
> If objBlock.IsXRef = True Then
> 'this is just to access the db,
> 'an error will occur if not loaded
> cnt = objBlock.XRefDatabase.Blocks.Count
> IsXrefResolved = True
> Else
> IsXrefResolved = False
> End If
> Exit Function
>
> ErrHandler:
> If Err.Number = -2145386390 Then
> IsXrefResolved = False
> Else
> MsgBox Err.Number & vbCrLf & Err.Description, vbCritical,
"function IsXrefResolved"
> End If
> End Function
>
> -Ed
>
>

Re:

Ed__Jobe — Fri, 10 May 2002 12:13:47 GMT

Good...assumptions can get ya. I get used to working in my own world sometimes. Thanks.

Re:

Ed__Jobe — Fri, 10 May 2002 12:24:55 GMT

In your function, I get an error at "objBlock.XRefDatabase.Blocks", "invalid use of property". That's why I had it checking the Count property.