请问DataTable用编程方法怎么设置单元格的对齐方式为居中？多谢

<asp:datagrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 16px; POSITION: absolute; TOP: 56px" runat="server"
Width="808px" Font-Names="宋体" BorderColor="#FFC0FF" CellPadding="2" HorizontalAlign="Center"
BorderWidth="1px" BorderStyle="Solid" AllowPaging="True" ForeColor="Blue" AutoGenerateColumns="False"
DataKeyField="nam" Height="320px">
<SelectedItemStyle BorderWidth="1px" BorderStyle="Dashed"></SelectedItemStyle>
<EditItemStyle BorderColor="#80FF80"></EditItemStyle>
<AlternatingItemStyle Wrap="False" HorizontalAlign="Center" Height="20px" BorderWidth="1px" ForeColor="Black"
BorderStyle="Solid" BorderColor="Black" BackColor="#80FFFF"></AlternatingItemStyle>
<ItemStyle Wrap="False" HorizontalAlign="Center" Height="20px" ForeColor="Blue" BorderStyle="Solid"
BorderColor="White" VerticalAlign="Middle" BackColor="#FFC080"></ItemStyle>ItemStyle 和 AlternatingItemStyle