导出EXCEL乱码的问题.

 有的页用这代码不乱码，一样的代码在下面的面就乱码，求高手。
public void ExpExcle(  GridView gridView)
    {
        Response.Clear();
        Response.Buffer = true;
        Response.Charset = "GB2312";
        Response.AppendHeader("Content-Disposition", "attachment;filename=FileName.xls");
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流为简体中文
        Response.ContentType = "application/ms-excel";//设置输出文件类型为excel文件。 
        this.EnableViewState = false;
        System.Globalization.CultureInfo myCItrad = new System.Globalization.CultureInfo("ZH-CN", true);
        System.IO.StringWriter oStringWriter = new System.IO.StringWriter(myCItrad);
        System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
        gridView.RenderControl(oHtmlTextWriter);
        Response.Write(oStringWriter.ToString());
        Response.End();    }
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="YfckMxList.aspx.cs" Inherits="yf_YfckMxList" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
   <title>药房出库明细</title>
<link href="../Css/Global.css" rel="stylesheet" type="text/css" />
    <link href="../Css/DataGrid.css" rel="stylesheet" type="text/css" />
      <script type="text/javascript" src="../Js/Prototype.js"></script>
        <script type="text/javascript" src="../Js/Functions.js"></script>
</head>
<body>
    <form id="form1" runat="server">
  <table cellpadding="2" cellspacing="1" id="Control">
    <tr>
      <td class="Header">&gt;&gt;药房出库明细
      <asp:TextBox ID="txtId" runat="server" Visible=false></asp:TextBox>
       <asp:TextBox ID="txtLb" runat="server" Visible=false></asp:TextBox>
       <asp:TextBox ID="txtId2" runat="server" Visible=false></asp:TextBox>
        <td class="Header">
     <input id="Button2" type="button" value="查询" class="XPButton" onclick="openSearchWin('YFCKMX');" />
  </td>
   <td class="Header"> <asp:Button id="ButtonExcle" runat="server" Text="导出"  class="XPButton" OnClick="ButtonExcle_Click"></asp:Button></td>
    </tr>
  </table>
    <div id=MainDiv>
          <asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True" CssClass="DataGrid"
            AutoGenerateColumns="False" CellPadding="4" DataSourceID="SqlDataSource1"
            ForeColor="#333333" GridLines="None"   PageSize="20"   Width="100%" Height="100%">
            <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
            <RowStyle BackColor="#EFF3FB" />
            <EditRowStyle BackColor="#2461BF" />
            <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
            <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
            <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
            <AlternatingRowStyle BackColor="White" />
            <Columns>
               
                <asp:BoundField DataField="ypmc" HeaderText="品名" SortExpression="ypmc" />
                <asp:BoundField DataField="ypgg" HeaderText="规格" SortExpression="ypgg" />
                <asp:BoundField DataField="BHYP" HeaderText="项目编号" SortExpression="BHYP" />
                <asp:BoundField DataField="LBYP" HeaderText="项目类别" SortExpression="LBYP" />
                <asp:BoundField DataField="DWRK" HeaderText="出库单位" SortExpression="DWRK" />
                <asp:BoundField DataField="JGRK" HeaderText="出库价格" SortExpression="JGRK" />
                <asp:BoundField DataField="SLRK" HeaderText="出库数量" SortExpression="SLRK" />
                <asp:BoundField DataField="JERK" HeaderText="出库金额" SortExpression="JERK" />
                <asp:BoundField DataField="HSL" HeaderText="换算率" SortExpression="HSL" />
                <asp:BoundField DataField="RQRK" HeaderText="出库时间" SortExpression="RQRK" />
                <asp:BoundField DataField="CZY" HeaderText="操作员" SortExpression="CZY" />
                <asp:BoundField DataField="LBRK" HeaderText="出库分类" SortExpression="LBRK" />
                 <asp:BoundField DataField="DKCCZ" HeaderText="出库编号" SortExpression="DKCCZ"  HeaderStyle-Width="20"/>
                 <asp:BoundField DataField="IDKCMX" HeaderText="出库明细编号" SortExpression="IDKCMX" />
                <asp:BoundField DataField="XH" HeaderText="序号" SortExpression="XH" />
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:yyConnectionString %>"
            SelectCommand="SELECT a.*,y.mc as ypmc,y.gg as ypgg FROM [V_YFRKMX] a,yp y where a.bhyp=y.bh and a.lbyp=y.lb ">
        </asp:SqlDataSource>
    
    </div>
    </form>
</body>
</html>
 <script language="javascript">
//打开查询窗体
function openSearchWin(lb)
{
var ss ="../publicFiles/Search.aspx?lb="+lb ;
openWindowA(ss);
}
//打开查询窗体后查询q
function reLoadPage(url)
{
 var surl='../yf/YfckMxList.aspx?sql=' + url ;
 window.location.href=surl ;
}
</script>