.net页面调试时闪下就丢失，求助！！急
代码调试时，页面闪下就丢失了，直接上代码；[code=C#][/code]<%@ Page Language="C#" MasterPageFile="~/SampleManager/Sample.Master" AutoEventWireup="true" CodeBehind="CreateSampleOrder.aspx.cs" Inherits="Flag.Net.SampleManager.CreateSampleOrder" Title="Create Sample Order" %>

<%@ Register Assembly="DevExpress.Web.ASPxGridView.v9.3.Export, Version=9.3.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"
Namespace="DevExpress.Web.ASPxGridView.Export" TagPrefix="dx" %>

<%@ Register Assembly="DevExpress.Web.ASPxGridView.v9.3, Version=9.3.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"
Namespace="DevExpress.Web.ASPxGridView" TagPrefix="dx" %>
<%@ Register Assembly="DevExpress.Web.ASPxEditors.v9.3, Version=9.3.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"
Namespace="DevExpress.Web.ASPxEditors" TagPrefix="dx" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<div>
<table border="0" cellpadding="0" cellspacing="0" style="width: 99%; height: 50px; position: relative; top: 0px;left:5px; z-index: 101;">
<tr>
<td style="height:25px; width: 563px;">
<asp:Button ID="btClear" runat="server" Text="Clear" /><asp:DropDownList ID="drpDType"
runat="server">
<asp:ListItem>ImportDate</asp:ListItem>
<asp:ListItem>ShipDate</asp:ListItem>
</asp:DropDownList>
<asp:TextBox ID="txtFrom" runat="server"></asp:TextBox>
<asp:Label ID="Label1" runat="server" Text="Factory" Width="59px"></asp:Label> 
<asp:TextBox ID="txtFactory" runat="server"></asp:TextBox>
<br />
<asp:Button ID="btnMore" runat="server" Text="MoreOption" Width="136px" />
<asp:Button ID="butQuery" runat="server" Text="Go" Width="51px" OnClick="butQuery_Click" />
 <asp:Button ID="btnCreate" runat="server" Text="Create Order" OnClick="btnCreate_Click" />
<asp:Button ID="butExport" runat="server" Text="Export Excel" OnClick="butExport_Click" />
<asp:Label ID="Label2" runat="server" Width="170px" BackColor="#FFFF80" BorderColor="Black"></asp:Label> 
</td>
</tr>
</table>
<dx:ASPxGridView ID="ASPxGridView1" runat="server" Width="872px" AutoGenerateColumns="False">
<Columns>
<dx:GridViewCommandColumn ShowSelectCheckbox="True" VisibleIndex="0" Width="30px">
<ClearFilterButton Visible="True">
</ClearFilterButton>
<HeaderStyle HorizontalAlign="Center" />

<HeaderTemplate>
<input id="Checkbox1" type="checkbox" onclick="ASPxGridView1.SelectAllRowsOnPage(this.checked);" />
</HeaderTemplate>
</dx:GridViewCommandColumn>
<dx:GridViewDataTextColumn Caption="Orderid" VisibleIndex="1" FieldName="Order_id">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="Itemid" VisibleIndex="2" FieldName="Item_ID">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="FactoryCode" VisibleIndex="3" FieldName="Factory_Code">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="ImportDate" VisibleIndex="4" FieldName="Data_entry_Date">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="Fob" VisibleIndex="5" FieldName="Fob_Code">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="AutoID" FieldName="AutoID" VisibleIndex="6">
</dx:GridViewDataTextColumn>
</Columns>
<SettingsPager PageSize="50">
</SettingsPager>
</dx:ASPxGridView>
<ajaxToolkit:PopupControlExtender ID="PopupControlExtender1" runat="server" PopupControlID="UpdatePanel1" TargetControlID="btnMore">
</ajaxToolkit:PopupControlExtender>
<asp:Panel ID="Panel1" runat="server" Height="92px" Width="233px">
<table border="0" cellpadding="0" cellspacing="0" width="180" style="background-color=DarkSeaGreen">
<tr>
<td>
<asp:RadioButton ID="Rad1" runat="server" GroupName="Pop" Text="Order_ID" Width="80px" />
<asp:RadioButton ID="Rad2" runat="server" GroupName="Pop" Text="Item_ID" Width="80px" /></td></tr>
<tr><td>
<asp:TextBox ID="txtWh" runat="server" Height="136px" TextMode="MultiLine" Width="160px"></asp:TextBox>
</td></tr>
<tr><td>
<asp:Button ID="btClearTxt" runat="server" Text="ClearText" /></td></tr>
</table>
</asp:Panel>
<ajaxToolkit:CalendarExtender ID="CalendarExtender1" runat="server" Format="yyyy-MM-dd"
PopupButtonID="txtFrom" TargetControlID="txtFrom">
</ajaxToolkit:CalendarExtender>
<dx:ASPxGridViewExporter id="ASPxGridViewExporter1" runat="server" ExportedRowType="Selected"
GridViewID="ASPxGridView1">
</dx:ASPxGridViewExporter>

</div>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Content>


[解决办法]
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