Casting DBobject to entity

[insiaiftiqhar]

this piece of code always gives "invalidcode exception". I tried both Ctype and DIrectCast.

Dim currentEntity As Entity = Nothing
                            Try
                                ' currentEntity = CType(myT.GetObject(id, OpenMode.ForRead), Entity)
                                currentEntity = DirectCast(myT.GetObject(id, OpenMode.ForRead), Entity)
                            Catch exp As OverflowException
                                Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("OverflowException")
                            Catch exp As InvalidCastException
                                Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("InvalidCastException")
                            End Try

Attached is the full function, I am trying to read all the " coincidence constraints" in a  drawing

Thanks in advance!

[Alfred.NESWADBA]

Hi,

Your loop scans through the BlockTable, so <id> represents the ObjectID for a BlockTableRecord. A BlockTableRecord is no entity (not derived from ...), so it can't be casted from DbObject to Entity.

- alfred -

[insiaiftiqhar]

Thank you for the response . How do I go about converting a blocktable reference to a block entity?  I need the entity to find its dependencies.

[Alfred.NESWADBA]

Hi,

>> How do I go about converting a blocktable reference to a block entity?

It's difficult, if we don't use the wordingbased on the API.

If you want to search for the blockdefinition (= BlockTableRecord) then you can use your loop through the BlockTable as you do and verify the ObjectID or the Name or whatever you need to find the correct block-definition,

If you want to search for block-insertions (= BlockReference) then you might

• use your <blocktablerecordobject>.GetBlockReferenceIDs to get all references in your drawing.
• get the block-insertions could be to create a filtered selectionset (>>>click<<<).

HTH, - alfred -