By quick google I found http://www.c-sharpcorner.com/Forums/ShowMessages.aspx?ThreadID=37243, not sure if helpful.

>>Hi,
>>When I create dataset designer generates for me tableadapter code where programmatically setup connection string
>>Now I want to use my userdefined function to initconnection instead function which generate designer for me
>>
>>For this purpose I create new partial class and create also InitConnection function, Then I delete function from desginer vb code
>>The problem is.. when I save XSD or build the application designer creates again and again.. and I'v got a compile time error
>>
>>"Error 11 'Private Sub InitConnection()' has multiple definitions with identical signatures"
>>
>>The question is - how can I make a SHADOW for designer code
>
>I don't think you can.
>IIRC one simple solution is to set the ConnectionModifier property of the TableAdapter to Public in the designer. That should allow you to access it directly in the constructor.
>(This from some sort of race memory so I could be wrong :-}
>>
>>
>>

>>Namespace Dci_datasetTableAdapters
>>
>>    Partial Public Class ProductsTableAdapter
>>
>>        Public Sub New(ByVal tcDBFilename As String)
>>            MyBase.New()
>>            Dim lcConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & tcDBFilename
>>            Pmks_connectionstring = lcConnectionString
>>            Me.ClearBeforeFill = True
>>        End Sub
>>
>>        Private _pmks_connectionstring As String
>>        Public Property Pmks_connectionstring() As String
>>            Get
>>                Return _pmks_connectionstring
>>            End Get
>>            Set(ByVal value As String)
>>                _pmks_connectionstring = value
>>            End Set
>>        End Property
>>
>>        Private Shadows Sub InitConnection()
>>            Me._connection = New Global.System.Data.OleDb.OleDbConnection
>>            Me._connection.ConnectionString = Pmks_connectionstring 
>>        End Sub
>>
>>    End Class
>>
>>End Namespace
>>