.NET

[#1]

my code is:

      Dim AcadDoc As Document = Application.DocumentManager.MdiActiveDocument
      Dim CurDb As Database = AcadDoc.Database
      Dim lt As LayerTable = DirectCast(tr.GetObject(CurDb.LayerTableId, OpenMode.ForRead), LayerTable)

 if fails on last line with error:-

Operation is not valid due to the current state of the object.

This works elsewhere.

Any ideas as to where to start looking?

[#2]

Hi,

my guess is:

your transaction "tr" is based on another database (and not based on CurDB)

- alfred -

[#3]

Actually no.

I didn't mean to confuse you by simplifying the code but

      AcadDoc = DocMan.MdiActiveDocument

      CurDb = AcadDoc.Database

are set when the DocumentActivated event is executed.

But I will look at my code again to see if this could be correct.

[#4 · Accepted solution]

My suggestion was going to be that it sounds like the kind of error you would get when trying to access the database from inside an eventhandler, when the database was not yet available.  Not sure what your purpose is, or if this will work for you, but one solution to that problem is to use the EventHandler to send a command to the stack (I use a P-Invoke of ads_queueexpr), which will execute as soon as AutoCAD has finished opening the drawing, and returned to a quiescent state.

[#5]

>> This works elsewhere.

>> Any ideas as to where to start looking?

---

I'd be looking at what is different since you used it 'elsewhere'  

... otherwise more information is required.

[#6]

Most of my code is in a common Module.

I also have a Command Class that loads forms, which raise events. I had started a transaction in the event and then called the Module code.

Now I start the transaction in the Module and it now works!

Thanks - you saved me a lot of time!

[#7]

This error happened to me under the following scenario, which I was able to fix:

I was iterating through block table records (OpenMode.ForRead) within a "Using" transaction block.  When a block matched certain criteria, I would call btr.UpgradeOpen, apply my modifications, then call tr.Commit.  This worked for the first block that matched the criteria  but not for the NEXT block that did, which failed with "Operation is not valid due to the current state of the object."

This was probably because the transaction had already been commited.  So to handle it, I added a boolean flag and set it to true where I had previously call tr.Commit.  I then checked for True AFTER finishing iterating through all block table records, and then called tr.commit.