redefining blocks with VB

[Anonymous]

Hi, i need some help getting started with vb development for autocad 2007.
First I am fairly confused about objectARX, VB.net etc, but i think i understand it enough to know that I can use vb to write code that i can load with the NETLOAD command from AutoCAD and execute it providing the commands i defined. so far so good.
Problem is that I am now trying to access/retrieve the list of all blocks that are defined in a drawing and I can't figure out how.

this is how i open the file:

Dim file as autodesk,autocad.applicationservices.document
file = application.documentmanager.open("myfile.dwg",false)

now that i have that file open i need to figure out how to get the blocks, find the one i am looking for (title block) and insert a new title block with the same name as the existing one so that i can redefine it.

any help will be appreciated, since the api docs are not offering a lot of help at this point since they don't show any examples.

thank you

[cadMeUp]

Why are you calling dispose on these two objects?:
bref.Dispose()
btr.Dispose()

[Anonymous]

not sure as i have not written the code. i am just trying to understand it and use it (modified if needed)
i found the code on this board. but it chokes before those lines anyway

[Anonymous]

You have created a new block reference. Before you can use AddNewlyCreatedDBObject you have to add the block reference to the database. The link I posted shows how to do it.

[Anonymous]

ok, now that makes sense. i will try it and post results. thanks for babysitting me

[Anonymous]

hey, where can i find the INSPECTOR app that is mentioned in the video. with the code as i have it now something weird is happening and i could use the inspector to see if my suspicion is correct.

[Anonymous]

ok guys, i really appreciate you helping me but so far it has barely worked. if i may ask you to look at the following code that i found on this board and may help me out figure out how to do this properly.

the code works fine in a sense, it will open the drawing i indicate and it will insert the new block which i get from another drawing.

my problem is this: the open dwg already has a block called TITLE-SQL, so by inserting another block with the same name should not work without redefining the block. However the new block is simply inserted without a name even though it is set in the code as you can see....

_
Public Sub blkTest()
Dim file As Autodesk.AutoCAD.ApplicationServices.Document
file = Application.DocumentManager.Open("C:\66535D.dwg", False)
Dim doc As Document = Application.DocumentManager.MdiActiveDocument
Dim ed As Editor = doc.Editor
Dim tr As Transaction = doc.TransactionManager.StartTransaction
Try
Dim dwgName As String = HostApplicationServices.Current.FindFile("C:\title-sql.dwg", _
Application.DocumentManager.MdiActiveDocument.Database, FindFileHint.Default)
Dim db As Database = New Database(False, False)
db.ReadDwgFile(dwgName, IO.FileShare.Read, True, "")
Dim NewBlkId As ObjectId
NewBlkId = doc.Database.Insert(dwgName, db, False)
Dim bt As BlockTable = tr.GetObject(doc.Database.BlockTableId, OpenMode.ForRead, True)
Dim btr As BlockTableRecord = tr.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForWrite, True)
Dim bref As BlockReference = New BlockReference(New Point3d(0.0, 0.0, 0.0), NewBlkId)
btr.AppendEntity(bref)
tr.AddNewlyCreatedDBObject(bref, True)
tr.Commit()
Catch ex As Exception
ed.WriteMessage(ex.ToString)
End Try
End Sub

[Anonymous]

The method I use (may not be the best way) is to:

get existing block references
delete existing block definition
create new block definition
assign new block definition to existing block references
insert new block reference


Heres the code:

Public Sub Insert()

Dim strBlock As String = "Your Block/DWG Name"
Dim strBlockPath As String = "Your Path to Block/DWG"

Dim objDB As Database = HostApplicationServices.WorkingDatabase
Dim objTrans As Transaction = objDB.TransactionManager.StartTransaction

Dim objBlockDefId As ObjectId = GetTableRecordId(objDB.BlockTableId, strBlock) 'Function Defined Below
Dim objBlockDef As BlockTableRecord
Dim objBlockRefs2Update As New ObjectIdCollection

'If BlockDef Exists Get All Block References To Be Updated And Then Delete BlockDef
If objBlockDefId <> ObjectId.Null Then
objBlockDef = CType(objTrans.GetObject(objBlockDefId, DatabaseServices.OpenMode.ForWrite, False), BlockTableRecord)
objBlockRefs2Update = objBlockDef.GetBlockReferenceIds(True, False)
objBlockDef.Erase()
End If

'Create New BlockDef From DWG
Dim objBlockDefDB As Database = New Database
objBlockDefDB.ReadDwgFile(strBlockPath, IO.FileShare.ReadWrite, False, "")
objBlockDefId = objDB.Insert(strBlock, objBlockDefDB, True)
objBlockDefDB.Dispose()

'Update Block References With New BlockDef
For Each objBlockRef2UpdateId As ObjectId In objBlockRefs2Update
Dim objBlockRef2Update As BlockReference = CType(objTrans.GetObject(objBlockRef2UpdateId, DatabaseServices.OpenMode.ForWrite, False), BlockReference)
objBlockRef2Update.BlockTableRecord = objBlockDefId
Next objBlockRef2UpdateId

objTrans.Commit()
objTrans.Dispose()

'Insert Block Reference At 0,0,0
objTrans = objDB.TransactionManager.StartTransaction
Dim objBlockRef As BlockReference = New BlockReference(New Point3d(0, 0, 0), objBlockDefId)
Dim objBT As BlockTable = CType(objTrans.GetObject(objDB.BlockTableId, DatabaseServices.OpenMode.ForWrite, False), BlockTable)
Dim objBTR As BlockTableRecord = CType(objTrans.GetObject(objBT(BlockTableRecord.ModelSpace), DatabaseServices.OpenMode.ForWrite, False), BlockTableRecord)
objBTR.AppendEntity(objBlockRef)
objTrans.AddNewlyCreatedDBObject(objBlockRef, True)
objTrans.Commit()
objTrans.Dispose()

End Sub

' This is a workaround for getting a non-erased SymbolTableRecord, when there are also erased ones with the same name
Public Function GetTableRecordId(ByVal objTableId As ObjectId, ByVal strName As String) As ObjectId
GetTableRecordId = ObjectId.Null
Dim objDB As Database = objTableId.Database
Dim objTrans As Transaction = objDB.TransactionManager.StartTransaction
Dim objTable As SymbolTable = CType(objTrans.GetObject(objTableId, DatabaseServices.OpenMode.ForRead, False), SymbolTable)
If objTable.Has(strName) Then
Dim objID As ObjectId
objID = objTable(strName)
If objID.IsErased Then
For Each objID In objTable
If Not objID.IsErased Then
Dim objSTR As SymbolTableRecord = CType(objTrans.GetObject(objID, DatabaseServices.OpenMode.ForRead, False), SymbolTableRecord)
If String.Compare(objSTR.Name, strName, True) = 0 Then
GetTableRecordId = objID
Exit For
End If
End If
Next
Else
GetTableRecordId = objID
End If
End If
objTrans.Commit()
objTrans.Dispose()
End Function

[Anonymous]

Nathan, this is exactly what I needed. Thank you so much.
There is only one issue left and I need a little more help. The block that I am looking for is called "TITLE-SQL" and it is the title block of the dwg.
your code does a wonderful job of replacing the existing one with the new one, however a warning comes up after your code executes that now I have more than one "*-SQL" block.
which is true because the existing one has been replaced, but there is also a new one inserted at 0,0,0.
When I type rename in AutoCAD and look at the blocks, i only see one TITLE-SQL listed though.

any ideas? since the current one is replaced. i really don't need to insert one at 0.0.0

[Anonymous]

never mind. I am blind as a bat. been dealing with this too long and cant even see the obvious any more

I just saw where you insert the block ref.
commented it out and all good
I truly appreciate all your help and larry's as well

[Anonymous]

hey nathan, is there any way to do this without having to open the dwg file(s)?

reason being is that I am having problems opening up dwg recursively. The code will open the first file and process it and then open the second one and just seemingly freeze. i can still interact with AutoCAD manually, but for some reason the code stops executing.

If I use the same code to recursively JUST list the file names, it works without any problems..

Thanks

_
Public Sub recreplace()
Recursion("C:\temp")
MsgBox("DONE")
End Sub

Sub Recursion(ByVal strFolder As String)
Try
Dim dirs As String() = Directory.GetDirectories(strFolder)
'Console.WriteLine("The number of directories is {0}.", dirs.Length)
Dim dir As String
For Each dir In dirs
'Debug.WriteLine(dir)
Dim f As String() = Directory.GetFiles(dir)
WriteDataToFile(f)
Recursion(dir)
Next
Dim filesCur As String() = Directory.GetFiles(strFolder)
WriteDataToFile(filesCur)

Catch ex As Exception
Console.WriteLine("The process failed: {0}", ex.ToString)
End Try
End Sub


Function WriteDataToFile(ByVal data() As String) As Boolean
Try
Dim en As System.Collections.IEnumerator
en = data.GetEnumerator
While en.MoveNext
If UCase(en.Current.Substring(en.Current.Length - 3)) = "DWG" Then
Debug.WriteLine(CStr(en.Current))
'Dim file As Autodesk.AutoCAD.ApplicationServices.Document
'file = Application.DocumentManager.Open(CStr(en.Current), False)
'file.LockDocument()
'Insert()
'file.CloseAndSave(CStr(en.Current))
'Debug.WriteLine(CStr(en.Current) & "," & Replace(UCase(en.Current.Substring(en.Current.lastindexof("\") + 1, 5)), ".DWG", ""))
End If
End While
Return True
Catch ex As Exception
MsgBox(ex.Message)
Return False
End Try

End Function

[Anonymous]

You need to run the command in application context.

Public Sub YourSubName()

After you have opened the document you need to create a DocumentLock using the LockDocument method of the document. Before you close the document you must call the Dispose method of the DocumentLock.

[Anonymous]

My post isn't displaying correctly. Read attached text file.

[Anonymous]

file = Application.DocumentManager.Open(CStr(en.Current), False)
file.LockDocument()
Insert()
file.CloseAndSave(CStr(en.Current))
file.Dispose()

i already have this, but it makes no difference

what do you mean by "application context"? is that achieved by CommandFlag.Session

[Anonymous]

Nathan,

I have finalized my code based on your suggestions, and it does work but every once in a while AutoCAD throws a fatal error. it is never at the same file and it appears quite random.

do you have any suggestions?

It will run for a while and do what it is supposed to do, but then it bombs out.

Thanks