The structure of my Document is as follows:

Part1

--- Annotations

--- Planes

--- Extrude1

I have used SelectionManager.GetSelectedObject6() method.

When I select the main Part/Assembly (Part1 in the above example) the Selection Manager returns an empty object.

How do I retrieve the main Part/Assembly?

The code I use is as below:

Sub GetSelectedObject( )

     Dim swApplication As SldWorks.SldWorks
     Dim swDoc As SldWorks.ModelDoc2
     Dim swCurrSelMgr As SldWorks.SelectionMgr
     Dim SelectedObject As Object
     Dim seltype As Long

     Set swApplication = GetObject(, "SldWorks.Application")
     If swApplication Is Nothing Then
          Exit Sub
     End If

     Set swDoc = swApplication.ActiveDoc

     Set swCurrSelMgr = swDoc.SelectionManager

     SelectedObjCount = swCurrSelMgr.GetSelectedObjectCount2(-1)

     seltype = swCurrSelMgr.GetSelectedObjectType3(iterator, -1)

     Set SelectedObject = swCurrSelMgr.GetSelectedObject6(1, -1)
     If SelectedObject Is Nothing Then
          MsgBox "Cannot select the Root Object.", vbExclamation
          Exit Sub
     End If

End Sub

This works fine if I select a feature/face in Part Document and a Part/Assembly in an Assembly Document.
The problem occurs when I select the Main Part/Assembly.
The "SelectedObject" is not valuated in this case. ie., the API "GetSelectedObject6" returns nothing.
Can you help me out?