更新面板，更新进度和下拉列表

Question

 <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true">
                  <Services>
            <asp:ServiceReference Path="Machine.asmx" />
         </asp:ScriptManager>
           <div align="center" style="width:auto" >
            <asp:UpdatePanel ID="up1" runat="server" Visible="true" UpdateMode="Conditional">
            <ContentTemplate> 
         <table class="nav-justified" border="1" id="table1">
             <tr>
                 <td>
                <asp:Label ID="Label2" runat="server" Text="Select Search Criteria"></asp:Label>
                 </td>
                 <td>
                     <asp:DropDownList ID="ddlSearchCriteria" runat="server" AutoPostBack="true" EnableViewState="true" OnSelectedIndexChanged="ddlSearchCriteria_SelectedIndexChanged" Height="30px" Width="200px">
                        <asp:ListItem Value="0">Select</asp:ListItem>
                         <asp:ListItem Value="1">All</asp:ListItem>
                          <asp:ListItem Value="2">Data Center</asp:ListItem>
                         </asp:DropDownList>
                 </td>
             </tr>
               <tr id="trDC" runat="server" visible="false"> <td>
                                    <asp:Label ID="lblRegion" runat="server" Text="Select DataCenter"></asp:Label>
                                </td>
                   <td>
                        <asp:DropDownList ID="ddlDC" runat="server" AutoPostBack="false" EnableViewState="true" OnSelectedIndexChanged="ddlDC_SelectedIndexChanged" Height="30px" Width="200px">
                                        <asp:ListItem Value="0">Select</asp:ListItem>
                                        <asp:ListItem Value="1">a </asp:ListItem>
                                    </asp:DropDownList></td>
               </tr>
           <tr id="tr1" runat="server" visible="false" >
               <td>
                   <asp:Label ID="lblOrder" runat="server" Text="Order For SOEID"></asp:Label>
               </td>
            <td >
                <asp:TextBox ID="txtOrderFor" runat="server" Height="20px" Width="200px"></asp:TextBox>
            </td>
               </tr>
             <tr>
                 <td>
                 </td>
                 <td>
                     <asp:Button ID="btnSearch" runat="server" Text="Search" OnClick="btnSearch_Click" />
                     <asp:Button ID="btnCancel" runat="server" Text="Cancel" OnClick="btnCancel_Click" />
                 </td>
             </tr>
         </table>
                 </div>
                 </ContentTemplate>
            </asp:UpdatePanel>
                    <asp:UpdateProgress ID="UpdateProgress1" runat="server" AssociatedUpdatePanelID="up1" DisplayAfter="0" DynamicLayout="false">
                        <ProgressTemplate>
                            <div style="position:absolute; left:45%;">
                                <div style="position:relative; left:45%;">
                                    <table border="0" align="center">
                                        <tr>
                                            <td>
                                             <img alt=""src="img/loading.gif" height="50px" width="50px" />
                                            </td>
                                        </tr>
                                    </table>
                                <center>
                                    Please wait...
                                </center>
                            </div>
                        </ProgressTemplate>
                    </asp:UpdateProgress>
                </div>
                
            
             <asp:UpdatePanel ID="up2" runat="server">
            <ContentTemplate> 
            <asp:Label ID="lblRows" runat="server" Font-Size="Large"  Visible="false" ></asp:Label>
                <asp:GridView ID="gvDetails" runat="server" AllowPaging="True" AutoGenerateColumns="False" CellPadding="3" CssClass="bootstrap dataTables_wrapper" DataKeyNames="Order_Item_Id”   EnableViewState="false" HeaderStyle-HorizontalAlign="Left" OnPageIndexChanging="gvDetails_PageIndexChanging" OnRowCommand="gvDetails_RowCommand" OnRowDataBound="gvDetails_RowDataBound" PageSize="15" ShowHeaderWhenEmpty="true" Visible="true" Width="100%">
                    <Columns>
                        <asp:TemplateField HeaderStyle-HorizontalAlign="Left" HeaderText="Select">
                      <ItemTemplate>
                          <asp:CheckBox ID="chkBox1" runat="server"  AutoPostBack="true" OnCheckedChanged="Check_Clicked"/>
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:BoundField DataField="Order_Item_Id" HeaderStyle-HorizontalAlign="Left" HeaderText="Order Id" />
                         
                    </Columns>
                </asp:GridView>
                </div>
                <asp:Button ID="Button4" runat="server" Font-Bold="True" Font-Size="XX-Large" OnClick="Button4_Click" Text="Export To Excel" visible="false" />
                <asp:Button ID="Button3" runat="server" Font-Bold="True" Font-Size="XX-Large" OnClick="Button3_Click" Text="Submit"  Visible="false"   />
                <asp:Button ID="Button1" runat="server" Font-Bold="True" Font-Size="XX-Large" OnClick="Button1_Click" Text="Cancel" Visible="false" />
                </div>
           </ContentTemplate>
                  <Triggers> 
                            <asp:PostBackTrigger ControlID="Button4" /> 
                           <asp:PostBackTrigger ControlID="Button3" />
                       <asp:PostBackTrigger ControlID="Button1" />
                        </Triggers> 
                 </asp:UpdatePanel>

我的aspx页面上有两个更新面板和1个更新进度。我的第一个更新面板包含两个下拉菜单，在第一个下拉菜单更改时，第二个填充，并且更新面板中还有一个提交按钮。 当我使用下拉菜单的selectedindexchange时，会发生自动回发，更新进度有效，但是我不希望它在该事件上起作用。它仅应在提交点击时起作用。 第二个更新面板包含单击提交按钮时显示的数据。 另外，我的更新进度不在任何更新面板中，而是在两个更新面板之间的div中。