Asp.Net：DropDownList中的服务器端还原客户端的SelectedItem [英] Asp.Net: Restoring client-side SelectedItem of DropDownList on server-side

问题描述

所以，我有我的网页上一个DropDownList包含几百个项目。用户可以通过输入一些文字到一个文本框筛选该DDL。该DDL然后获取相应的过滤（不包含输入的文本中的所有项目都通过JavaScript删除）。然后，用户选择他的产品和presses一个按钮。通常情况下，因为DDL已经改变，这将导致错误和ASP验证回发数据。然而，随着 EnableEventValidation =FALSE
您可以关闭此行为，并在页面才能正确submited。但是，（这就是我的问题）：在DDL的selectedIndex始终为0的服务器端，因而则selectedItem是错误的。所以，很显然，在客户端的变化被解雇。是否有人对如何得到正确的SelectedItem的想法？或者更好的方式来筛选DDL和保持正确的SelectedItem？

So I have a dropDownList on my page that contains hundreds of items. The user can filter this DDL by typing some text into a textbox. The DDL then gets filtered accordingly (all items that do not contain the entered text are removed via JavaScript). The user then selects his item and presses a button. Usually, this would cause an error because the DDL has been altered and ASP validates the PostBack data. However, with EnableEventValidation="false" you can turn off this behavior and the page gets submited properly. But (and thats my problem): the SelectedIndex of the DDL is always "0" on server-side and thus the SelectedItem is the wrong one. So obviously, the changes on client-side are dismissed. Does anybody have an idea on how to get the correct SelectedItem? Or a better way to filter a DDL and maintain the correct SelectedItem?

推荐答案

当用户presses使用jQuery按钮获取下拉列表的当前值，并将其设置在隐藏字段页面上，给隐藏字段=服务器，这样当它回发，你会得到选择该值。
例如：

When user presses a button get current value of dropdown using jQuery and set it in hidden field on page , give hidden field runat="server" so that when it posts back you will get value that was selected. For example

    <asp:DropDownList class="myList"></asp:DropDownList>
    <asp:Button class="btn"/> 
    <input type="hidden" id="hdnSelectedI" runat="server" class="hiddenControl"> 

    $(document).ready(function(){

    $(".btn").click(function(){

      var selectedItem = $(".myList").val();
      $(".hiddenControl").val(selectedItem);  

    });

});

我用CLAS名选择在ASPNET ID是自动生成的。在服务器端获取的价值
hdnSelectedItem.Value ，并从项目列表中拉/ DB维护服务器。

I have used clas name selector as ids in aspnet are auto generated. On server side get value of hdnSelectedItem.Value , and from that pull from list of items/db maintained on server.

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