Asp.Net母版页元素ID不一致的体现

Asp.Net母版页元素ID不一致的体现

来自森大科技官方博客   http://www.cnsendblog.com/index.php/?p=104

<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" Theme="style" AutoEventWireup="true"
     CodeFile="r_Balance.aspx.cs" Inherits="Report_r_Balance" %>

<asp:Content ID="content" ContentPlaceHolderID="MainContent" runat="server">

  

     <form id="form1" runat="server">
         <div>
             <table class="topTable" cellspacing="0" cellpadding="0" border="0">
                 <tbody>
                     <tr class="title">
                         <td>
                             <asp:Label ID="lbPagename" runat="server" SkinID="title" Text="余额统计"></asp:Label>
                         </td>
                     </tr>
                     <tr class="butt">
                         <td>
                             <asp:ImageButton ID="btnPrint" runat="server" SkinID="b_print" OnClick="btnPrint_Click" />
                             <asp:ImageButton ID="btnExport" runat="server" SkinID="b_export" OnClick="btnExport_Click" />
                         </td>
                     </tr>
                 </tbody>
             </table>
             <!--结束功能条-->
             <table border="1" style="font: 宋体; font-size: 12px;">
                 <tr>
                                     <td align="center" style="width: 256px; height: 15px;">
                         卡号*</td>
                     <td colspan="1" style="width: 233px; height: 15px">
                         <asp:TextBox ID="txtc_printno" runat="server"></asp:TextBox></td>
                     <td colspan="1" style="height: 24px; font-size: 14px; font-family: 宋体; width: 180px;"
                         align="center">
                         <asp:ImageButton ID="nSearch" runat="server" AlternateText="查询" ImageAlign="Middle"
                             ImageUrl="~/images/go.gif" OnClick="nSearch_Click" />
                     </td>
                 </tr>
             </table>

....

生成的HTML代码：

   <form name="aspnetForm" method="post" action="r_Balance.aspx" id="aspnetForm">

<table class="topTable" cellspacing="0" cellpadding="0" border="0">
                 <tbody>
                     <tr class="title">
                         <td>
                             <span id="ctl00_MainContent_lbPagename" style="display:inline-block;color:#F2F3F9;border-style:None;font-family:宋体;font-size:13px;height:22px;">余额统计</span>
                         </td>
                     </tr>
                     <tr class="butt">
                         <td>
                             <input type="image" name="ctl00$MainContent$btnPrint" id="ctl00_MainContent_btnPrint" src="../App_Themes/style/images/b_print.jpg" align="middle" onclick="return np();" style="border-style:Ridge;border-width:0px;" />
                             <input type="image" name="ctl00$MainContent$btnExport" id="ctl00_MainContent_btnExport" src="../App_Themes/style/images/b_export.jpg" align="middle" style="border-style:Ridge;border-width:0px;" />
                         </td>
                     </tr>
                 </tbody>
             </table>
             <!--结束功能条-->
             <table border="1" style="font: 宋体; font-size: 12px;">
                 <tr>

                     <td align="center" style="width: 256px; height: 15px;">
                         卡号*</td>
                     <td colspan="1" style="width: 233px; height: 15px">
                         <input name="ctl00$MainContent$txtc_printno" type="text" id="ctl00_MainContent_txtc_printno" style="width:120px;height:16px;font-size:12px;font-family:宋体;color:DimGray;border-width:1px;border-style:Solid;border-color:#C4CAE6;" /></td>
                     <td colspan="1" style="height: 24px; font-size: 14px; font-family: 宋体; width: 180px;"
                         align="center">
                         <input type="image" name="ctl00$MainContent$nSearch" id="ctl00_MainContent_nSearch" src="../images/go.gif" alt="查询" align="middle" onclick="return nselect();" style="border-width:0px;" />
                     </td>
                 </tr>
             </table>

注意：

1.源文件控件和元素ID和生成HTML文件的ID不一致。在生成的HTML中原ASP控件ID加了ctl00_MainContent_前缀，其他元素加了ctl00$MainContent$前缀。原变form1为aspnetForm这是因为aspx页面的控件是母板页的ContentPlaceHolder
控件下的子控件,所以控件ID会变

2.<system.Web><xhtmlConformance mode="Transitional|Legacy|Strict" />在其中选择 Transitional、Strict则产生自动前缀。ctl00.选择 Legacy|则产生自动前缀_ctl0.

3.后台Request.Form["txtc_name"]键值需要改变，必须变为Request.Form["ctl00$MainContent$txtc_name"]才能收到页面输入值

4.至于为什么，只能说这是.NET机制问题。。。