请教高手：.NET 2.0 C#中的GridView控件的列想根据用户查询内容的不同来设置各个列的位置？ 有什么代码能实现各个列位置的替换？ 先谢谢了。
<Columns>
<asp:BoundField DataField= "fanshi " HeaderText= "方式 " SortExpression= "fanshi " />
<asp:BoundField DataField= "media " HeaderText= "媒体 " SortExpression= "media " />
<asp:BoundField DataField= "riqi " HeaderText= "时段 " SortExpression= "riqi " />
<asp:BoundField DataField= "xxhd " HeaderText= "宣传活动 " SortExpression= "xxhd " />
<asp:BoundField DataField= "xxnr " HeaderText= "宣传内容 " SortExpression= "xxnr " />
<asp:BoundField DataField= "times " HeaderText= "次数 " />
<asp:BoundField DataField= "places " HeaderText= "地点 " />
<asp:BoundField DataField= "zxdw " HeaderText= "执行单位 " SortExpression= "zxdw " />
<asp:BoundField DataField= "opendate " DataFormatString= "{0:yyyy-MM-dd} " HeaderText= "开始日期 "
HtmlEncode= "False " />
<asp:BoundField DataField= "enddate " DataFormatString= "{0:yyyy-MM-dd} " HeaderText= "结束日期 "
HtmlEncode= "False " />
<asp:BoundField DataField= "memoshi " HeaderText= "备注 " SortExpression= "memoshi " >