locking layers in a routine with a new database not working

[Anonymous]

Awhile back I was trying to get some stuff to work & somewhere stumbled upon some code that created a new database object from a filename. I didn't really understand it, but it seemed to work, so fine.

Now I'm trying to add some features to my routine & the following code is not working:

    Shared Function LayerLockDB(ByVal dwgFileName As String, ByVal LayerName As String) As Boolean



        LayerLockDB = False

        Dim acLayerTable As LayerTable
        Dim acLyrTblRec As LayerTableRecord
        Dim myLayerId As ObjectId

        Dim myDb As New Database(False, True)

        myDb.ReadDwgFile(dwgFileName, FileOpenMode.OpenForReadAndAllShare, False, "")

        Using acTrans As Transaction = myDb.TransactionManager.StartTransaction

            Try     ' verify layer exists - If Layer Exist recover LayerID

                acLayerTable = CType(acTrans.GetObject(myDb.LayerTableId, OpenMode.ForRead, True, True), LayerTable)

                myLayerId = acLayerTable.Item(LayerName)

                If myLayerId.IsErased Then          ' If Deleted, Recover Layer

                    acLayerTable.UpgradeOpen()
                    acLayerTable.Item(LayerName).GetObject(OpenMode.ForWrite, True, True).Erase(False)

                End If

            Catch ex As Exception               ' Layer Doesn't Exist: Create it

                CreateLayerDB(dwgFileName, LayerName, 7)

                acLayerTable = CType(acTrans.GetObject(myDb.LayerTableId, OpenMode.ForRead, False), LayerTable)     ' Recover LayerID of newly created Layer

            End Try

            acLyrTblRec = acTrans.GetObject(acLayerTable(LayerName), OpenMode.ForWrite)

            acLyrTblRec.IsLocked = True  ' lock layer

            LayerLockDB = True

            acTrans.Commit()

        End Using

        myDb.Dispose()

    End Function

dwgfilename in this case is the name of the current dwg.

I get no erros when running/debugging this, but my layer remains unlocked.

I'm guessing it has to do with the new database object, as if the layer is locked in that database but is not updated in the current dwg.

I guess, fundementally I need to understand what this:

myDb.ReadDwgFile(dwgFileName, FileOpenMode.OpenForReadAndAllShare, False, "")

 is trying to do & why it seemed like I needed it in the first place (note my original program (where I thought this worked) opens many drawings & lock a particular layer in them all)

[Anonymous]

I see nothing wrong with your code, it's working. However, you forgot to save changes back to database. Just add the code myDb.SaveAs(myDb.Filename, DwgVersion.Current) before myDb.Dispose() and it's good to go.

private static bool LayerLockDB(string dwgFileName, string layerName)
{
    bool functionReturnValue;
    var myDb = new Database(false, true);
    myDb.ReadDwgFile(dwgFileName, FileOpenMode.OpenForReadAndAllShare, false, "");
    using (Transaction acTrans = myDb.TransactionManager.StartTransaction())
    {
        // verify layer exists - If Layer Exist recover LayerID
        LayerTable acLayerTable;
        try
        {
            acLayerTable = (LayerTable)acTrans.GetObject(myDb.LayerTableId, OpenMode.ForRead, true, true);
            ObjectId myLayerId = acLayerTable[layerName];
            // If Deleted, Recover Layer
            if (myLayerId.IsErased)
            {
                acLayerTable.UpgradeOpen();
                acLayerTable[layerName].GetObject(OpenMode.ForWrite, true, true).Erase(false);
            }
            // Layer Doesn't Exist: Create it
        }
        catch (System.Exception ex)
        {
            CreateLayerDB(dwgFileName, layerName, 7);
            acLayerTable = (LayerTable)acTrans.GetObject(myDb.LayerTableId, OpenMode.ForRead, false);
            // Recover LayerID of newly created Layer
        }
        var acLyrTblRec = (LayerTableRecord)acTrans.GetObject(acLayerTable[layerName], OpenMode.ForWrite);
        acLyrTblRec.IsLocked = true;
        // lock layer
        functionReturnValue = true;
        acTrans.Commit();
    }

    // Update the current database with the new locked layer
    myDb.SaveAs(myDb.Filename, DwgVersion.Current);
    myDb.Dispose();
    return functionReturnValue;
}

-Khoa

[Anonymous]

Thanks. That seems like the exact sort of thing that it was missing.

[Anonymous]

You are welcome. Glad to see it works.

-Khoa