在新弹出页面下载

<div id="icaption">
        <div id="title">
            XML配置管理
        </div>
        <a id="btn_add" title="添加菜单" runat="server" href="AddSampleXml.aspx"></a>
    </div>
    <div id="itable">
        <asp:GridView ID="gv_Menu" runat="server" GridLines="None" BorderWidth="0px" CellPadding="0"
            CellSpacing="1" align="center" AutoGenerateColumns="false" OnRowCommand="gv_department_RowCommand">
            <Columns>
                <asp:TemplateField HeaderText="名称">
                    <ItemTemplate>
                        <%#((System.Data.DataRowView)Container.DataItem)["ACTION"]%>
                    </ItemTemplate>
                    <ItemStyle Width="25%" />
                </asp:TemplateField>
                <asp:TemplateField HeaderText="下载">
                    <ItemTemplate>
                        <a href="xmlDetails.aspx?item=<%#Eval("Id") %>">下载</a>
                    </ItemTemplate>
                    <ItemStyle Width="25%" />
                </asp:TemplateField>
                <asp:TemplateField HeaderText="描述">
                    <ItemTemplate>
                        <%#((System.Data.DataRowView)Container.DataItem)["DESCRIPTION"]%>
                    </ItemTemplate>
                    <ItemStyle Width="25%" />
                </asp:TemplateField>
                <asp:TemplateField HeaderText="操作">
                    <ItemTemplate>
                        <a href="AddSampleXml.aspx?ID=<%#Eval("ID") %>" title="编辑">
                            <img src="../App_Themes/images/btn_edit.png" alt="编辑" border="0" />
                        </a>
                        <asp:LinkButton runat="server" CommandName="Del" CommandArgument='<%#Eval("ID") %>'
                            OnClientClick="return window.confirm('您确定要删除该xml吗?')" ID="lkDelete" CausesValidation="false"
                            ToolTip="删除"><img src="../App_Themes/images/btn_delete.png" border="0" />
                        </asp:LinkButton>
                    </ItemTemplate>
                    <ItemStyle Width="25%" />
                </asp:TemplateField>
            </Columns>
            <RowStyle CssClass="tr3" Font-Size="12px" Height="28px" />
            <HeaderStyle CssClass="itable_title" />
            <EmptyDataTemplate>
                <tr class="itable_title">
                    <th width="25%">
                        名称
                    </th>
                    <th width="25%">
                        查看
                    </th>
                    <th width="25%">
                        描述
                    </th>
                    <th width="25%">
                        操作
                    </th>
                </tr>
                <tr class="tr3">
                    <td class="grid_no_result" colspan="4">
                        <span>当前没有查询记录</span>
                    </td>
                </tr>
            </EmptyDataTemplate>
        </asp:GridView>
    </div>

新页面的后台

    BLL.NeoSampleXmlBll bll = new BLL.NeoSampleXmlBll();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!string.IsNullOrEmpty(Request.QueryString["item"]))
        {
            DataTable dt = bll.GetNeoSampleXmls(Request.QueryString["item"]);
            if (dt == null)
            {
                return;
            }
            string content = dt.Rows[0]["content"].ToString();
            string action = dt.Rows[0]["action"].ToString();
            XmlDocument doc = new XmlDocument();
            doc.LoadXml(content);
            string s = doc.OuterXml; ;
            StringWriter sw = new StringWriter();
            sw.WriteLine(s);
            Response.AddHeader("content-disposition", "attchment;filename=" + action + ".xml");
            Response.ContentEncoding = Encoding.GetEncoding("gb2312");
            Response.ContentType = "application/xml";
            Response.Write(sw.ToString());
            Response.Flush();
            Response.End();
        }
    }