ComboBox not filled with DataTable - Why?

[VBobCat]

I used this code:

Friend Sub PopulateCB(ByRef mycontrol As ComboBox, _
                      ByVal expressionSQL As String)
    ' DMBD is my data-handling class:
    Using DataTableOrigem As DataTable = DMBD.Read_a_Table(expressionSQL)
        ' this MsgBox told me my Table is correctly filled:
        MsgBox(DataTableOrigem.Rows(0).Item(0).ToString)
        ' this MsgBox told me my control was correctly passed:
        MsgBox(mycontrol.Name)
        mycontrol.DataSource = DataTableOrigem
        mycontrol.ValueMember = DataTableOrigem.Columns(0).ColumnName
        mycontrol.DisplayMember = DataTableOrigem.Columns(1).ColumnName
    End Using
End Sub

Nevertheless, mycontrol remains empty after this.

Could someone help me figure out why?

Thank you very much!

[mbutler755]

I would use a binding source and table adapter to accomplish this. Which version of VS are you using?

[VBobCat]

I am not so sure about how to do so...

What I can say, in order to clarify, is this: my data source is an Access 12 file (.accdb), and all the OleDb commands I use to handle it are encapsulated in that DMDB class. I need to fill this ComboBox which data that are loaded in application's startup, and remain in disconnected DataTable, for it will not change along runtime (they are actually long category lists, so I decided to load them only once, to avoid network traffic overhead).

I am using VS 2010 Express, over VB.NET, Framework version #4.

Thank you very much!

[VBobCat]

My own mistake. I just have been told about it. Using statement disposes the used resource at end of block, so I have disposed the DataTable and, with it, all ComboBox data, which was bound and referred to that DataTable.

I've already tested the fixed code. It made all ok and it is, also, far more elegant:

Friend Sub PopulateCB(ByRef mycontrol As ComboBox, ByVal expressionSQL As String)
     mycontrol.DataSource = DMBD.Read_a_Table(expressionSQL)
     mycontrol.ValueMember = DirectCast(mycontrol.DataSource, DataTable).Columns(0).ColumnName
     mycontrol.DisplayMember = DirectCast(mycontrol.DataSource, DataTable).Columns(1).ColumnName
End Sub

Thanks to all of you that spent some thinking over the question!