how to fill datagridview from a class?

I have a class filldatagrid.vb

  Private Function Getdata(ByVal selectCommand As String) As DataTable

        Dim conn As String = ConfigurationManager.ConnectionStrings("CnnStr").ToString()
        Dim adapter As New OracleDataAdapter(selectCommand, conn)
        Dim data As New DataTable()
        adapter.Fill(data)
        Return data
    End Function

in the form how do i call this class and fill the gridview