' Create an empty list.
Dim Rows As New ArrayList()
' Add the selected rows to the list.
Dim I As Integer
For I = 0 To GridView1.SelectedRowsCount() - 1
   If (GridView1.GetSelectedRows()(I) >= 0) Then 
     Rows.Add(GridView1.GetDataRow(GridView1.GetSelectedRows()(I)))
   End If
Next
Try
   GridView1.BeginUpdate()
   For I = 0 To Rows.Count - 1
      Dim Row As DataRow = CType(Rows(I), DataRow)
      ' Change the field value.
      Row("Discontinued") = True
   Next
Finally
   GridView1.EndUpdate()
End Try