<DataGrid x:Name="dgvOrderItems" AutoGeneratedColumns="DgvOrderItems_AutoGeneratedColumns" Height="570" VerticalAlignment="Stretch" Width="auto" HorizontalAlignment="Stretch" FontSize="10" Padding="0" Margin="0,20,0,0" ></DataGrid>

dgvOrderItems.SelectionUnit = DataGridSelectionUnit.FullRow;
dgvOrderItems.IsReadOnly = true;
dgvOrderItems.ColumnHeaderHeight = 15;
dgvOrderItems.Columns[0].Header = "Order Item";
dgvOrderItems.Columns[0].Width = 113;
dgvOrderItems.Columns[1].Visibility = Visibility.Hidden;
dgvOrderItems.Columns[2].Header = "Qty.";
dgvOrderItems.Columns[2].Width = 25;