asp.net内容页的CascadingDropDown有问题

Question

我有一个带有更新面板的asp.net内容页面，带有ajax扩展器的asp.net控件，还有带有事件点击的asp.net按钮。除了一个案例之外，一切都很正常。我有3个带CascadingDropDown扩展器的DropDownList。当我在没有从DropDownLists中选择任何东西的情况下点击按钮，然后点击按钮，事件点击将正常工作，但是如果我选择了任何东西，当我点击按钮时，我的页面将会响应。

我已经为点击按钮添加了触发器。

有什么我应该检查来解决这个问题的吗？

下面是我的代码：

<%@ Page Title="" Language="C#" MasterPageFile="~/Master.Master" AutoEventWireup="true" CodeBehind="WebForm2.aspx.cs" Inherits="IMAM_APPLICATION.WebForm2" %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
</asp:Content>
<asp:Content ID="Content3" ContentPlaceHolderID="ContentPlaceHolder2" runat="server">
  <asp:UpdatePanel ID="UPDDL" runat="server">
     <ContentTemplate>
     <asp:Panel ID="PDDL" runat="server">
      <asp:DropDownList ID="cmbWorkField" runat="server" Style="top: 41px; left: 126px;
                    position: absolute; height: 22px; width: 126px">


                </asp:DropDownList>

                <asp:DropDownList runat="server" ID="cmbOccupation" Style="top: 77px; left: 127px;
                    position: absolute; height: 22px; width: 77px">

                </asp:DropDownList>
                <asp:DropDownList ID="cmbSubOccup" runat="server"
                    style="position:absolute; top: 116px; left: 126px;">

                </asp:DropDownList>

                <cc1:CascadingDropDown ID="cmbWorkField_CascadingDropDown" runat="server"
                    TargetControlID="cmbWorkField"
                    Category="WorkField"  
                    LoadingText="Please Wait ..."
                    PromptText="Select Wor kField ..."
                    ServiceMethod="GetWorkField"
                    ServicePath="ServiceTags.asmx">
                </cc1:CascadingDropDown>

                <cc1:CascadingDropDown ID="cmbOccupation_CascadingDropDown" runat="server"

                    TargetControlID="cmbOccupation"
                     Category="Occup"
                    LoadingText="Please wait..."
                    PromptText="Select Occup ..."
                    ServiceMethod="GetOccup"
                    ServicePath="ServiceTags.asmx"
                    ParentControlID="cmbWorkField">
                </cc1:CascadingDropDown>
                <cc1:CascadingDropDown ID="cmbSubOccup_CascadingDropDown" runat="server"
                    Category="SubOccup"
                    Enabled="True"
                     LoadingText="Please Wait..."
                    ParentControlID="cmbOccupation"
                    PromptText="Select Sub Occup"
                    ServiceMethod="GetSubOccup"
                    ServicePath="ServiceTags.asmx"
                    TargetControlID="cmbSubOccup">
                </cc1:CascadingDropDown>
                </asp:Panel>
         <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
         <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
     </ContentTemplate>

      <Triggers>
          <asp:AsyncPostBackTrigger ControlID="Button1" EventName="Click" />
      </Triggers>

     </asp:UpdatePanel>


</asp:Content>

........................

here is the code behind:

....................................................

protected void Button1_Click(object sender, EventArgs e)
        {
            Label1.Text = "you click me";
        }

Answer 1

我能够解决这个问题。

我添加的是删除更新面板，并将页面的EnableEventValidation=设置为“False”。

Answer 2

您看到的问题记录在Codeplex上。请参阅jlewicki的帖子，了解其他两种不需要关闭EventValidation的可能解决方案。