AsyncPostBackTrigger仅在第一次工作 [英] AsyncPostBackTrigger works only the first time

问题描述

我有一个包含gridview的更新面板. 该网格具有一个下拉列表列.

I have an update panel that includes a gridview. This grid has a drop down list column.

测试版aspx代码:

<asp:UpdatePanel ID="UpdatePanel1" runat="server" EnablePartialRendering="false" UpdateMode="Conditional"> 

...
  <asp:GridView ID="Gv_Queue" runat="server">

    <Columns>

      <asp:TemplateField HeaderText="H">
        <ItemTemplate>
          <asp:DropDownList ID="ddl_proprietà" runat="server" OnSelectedIndexChanged="ddl_proprietà_SelectedIndexChanged" AutoPostBack="true"/>
        </ItemTemplate>

    </Columns>

  </asp:GridView

</asp:UpdatePanel>

我通过代码在UpdatePanel中添加DDL的触发器:

I add the triggers of the DDL in the UpdatePanel by code:

AsyncPostBackTrigger trigger = new AsyncPostBackTrigger();
trigger.ControlID = dl.UniqueID;  //dl is the Drop Down control
UpdatePanel1.Triggers.Add(trigger);

在第一个selectedIndexChanged事件上效果很好...但是第二次触发该事件时，触发器无法正常运行，因为运行了回发操作.

It works good at the fist selectedIndexChanged event... but the second time that the event is fired the trigger does not work correctly because a post back operation runs.

我已经尝试过:

• 要将AsyncPostBackTrigger更改为PostBackTrigger，但缺少 抛出组件异常.
• 将UpdatePanel属性中的updateMode更改为始终".
• 仅在
  的ItemTemplate列中放置另一个UpdatePanel 下拉菜单.

• to change the AsyncPostBackTrigger to a PostBackTrigger but a missing component exception is thrown.
• change the updateMode in theUpdatePanel attribute to 'Always'.
• Put another UpdatePanel in the ItemTemplate Column only for the
  DropDown.

推荐答案

在我的情况下，问题是因为页面上有2个具有相同ID的控件.如果以前的答复不能解决问题，则可能需要检查一下.

In my case the issue was because I had 2 controls on the page with the same Id. You may want to check this out if the previous responses did not resolve the issue.

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