我一直在使用模态弹出窗口这个奇怪的问题。出于某种原因，当我选择下拉项时，我的更新按钮不会触发点击事件。但随后我将下拉列表保留为默认值，更新按钮工作正常。
这是我的aspx页面代码
<asp:Button ID="Button1" CssClass="hide" runat="server" Text="Button" />
<ajaxToolkit:ModalPopupExtender runat="server" ID="cfPopUp" PopupControlID="Panel4"
TargetControlID="Button1" OkControlID="cfUpdateBtn" CancelControlID="cfCancelBtn" />
<asp:Panel ID="Panel4" runat="server" CssClass="modalPopup">
<asp:UpdatePanel ID="UpdatePanel2" runat="Server">
<ContentTemplate>
<asp:Panel ID="Panel13" CssClass="" runat="server">
<asp:Panel ID="Panel14" CssClass="" runat="server">
<div style="padding: 10px; border: 3px solid black; background-color: White; color: Black;">
<asp:Label ID="Label25" Width="200px" runat="server" Text="Health and Safety Net" /><div
class="seperator">
</div>
<table class="style143">
<tr>
<td class="style185">
<asp:Label ID="cfCategorylbl" runat="server" Text="Category:"></asp:Label>:
</td>
<td>
<asp:DropDownList ID="cbFactors_Categories" runat="server" Width="350px" Font-Names="Tahoma"
Font-Size="Small" ForeColor="DimGray" Height="24px" CssClass="style75">
</asp:DropDownList>
<ajaxToolkit:CascadingDropDown ID="CascadingDropDown3" runat="server" TargetControlID="cbFactors_Categories"
Category="categories" ServiceMethod="getCategory" ServicePath="~/2012/IrSubmitWebService.asmx"
PromptText="Select Category" />
</td>
<td align="center" rowspan="3" valign="top">
<asp:Label ID="lblFactor_ID" runat="server" Font-Names="Tahoma" Font-Size="Small"
ForeColor="DimGray" Style="font-style: italic" TabIndex="56"></asp:Label>
<cc1:DynamicPopulateExtender ID="lblFactor_ID_DynamicPopulateExtender" runat="server"
Enabled="True" TargetControlID="lblFactor_ID" BehaviorID="dp1" ServiceMethod="getFactorID"
ServicePath="~/2012/IrSubmitWebService.asmx">
</cc1:DynamicPopulateExtender>
<hr class="style157" />
<asp:Label ID="cfID" runat="server" Font-Names="Tahoma" Font-Size="Small" ForeColor="DimGray"
Style="font-style: italic" Width="400px" TabIndex="57"></asp:Label>
</td>
</tr>
<tr>
<td class="style185">
<asp:Label ID="cfTypeslbl" runat="server" Text="Type:"></asp:Label>
</td>
<td>
<asp:DropDownList ID="cbFactors_Types" runat="server" ForeColor="DimGray" Height="24px"
TabIndex="54" Width="350px" Font-Names="Tahoma" Font-Size="Small" CssClass="style75">
</asp:DropDownList>
<cc1:CascadingDropDown ID="cbFactors_Types_CascadingDropDown" runat="server"
TargetControlID="cbFactors_Types" ParentControlID="cbFactors_Categories" Category="type"
ServiceMethod="getTypeofAction" ServicePath="~/2012/IrSubmitWebService.asmx"
PromptText="Select Type">
</cc1:CascadingDropDown>
</td>
</tr>
<tr>
<td class="style185">
<asp:Label ID="cfFactorslbl" runat="server" Text="Factor:"></asp:Label>
</td>
<td>
<asp:DropDownList ID="cbFactors_Factors" runat="server" ForeColor="DimGray" Height="24px"
TabIndex="55" Width="350px" Font-Names="tahoma" Font-Size="Small" CssClass="style75">
</asp:DropDownList>
<cc1:CascadingDropDown ID="cbFactors_Factors_CascadingDropDown" runat="server"
TargetControlID="cbFactors_Factors" ParentControlID="cbFactors_Types" Category="category"
ServiceMethod="getFactor" ServicePath="~/2012/IrSubmitWebService.asmx" PromptText="Select Factor">
</cc1:CascadingDropDown>
</td>
</tr>
<tr>
<td class="style185">
<asp:Label Text="Justification:" ID="cfJustificationlbl" runat="server"></asp:Label>
</td>
<td colspan="2">
<asp:TextBox ID="txtJustification" runat="server" ForeColor="DimGray" Height="29px"
Style="font-family: Tahoma; font-size: small" TabIndex="56" TextMode="MultiLine"
ToolTip="Provide a justification for this factor." Width="775px" Font-Names="Tahoma"
Font-Size="Small"></asp:TextBox>
</td>
</tr>
</table>
<br />
<div style="text-align: center">
<asp:Button CausesValidation="false" ID="cfUpdateBtn" runat="server"
Text="Update" CssClass="button" /><span style="margin-left: 10px"><asp:Button CausesValidation="false"
ID="cfCancelBtn" runat="server" Text="Cancel" CssClass="button" /></span></div>
</div>
</asp:Panel>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
我的更新后面的代码（它只是关闭弹出窗口）
Protected Sub cfUpdateBtn_Click(sender As Object, e As EventArgs) Handles cfUpdateBtn.Click
cfPopUp.Hide()
End Sub
对于我的生活，我无法弄清楚为什么当下拉列表不是默认值时更新按钮不起作用。
感谢您的帮助
答案 0 :(得分：0)
可能的原因可能是您将下拉列表与Web服务绑定在一起。每当您点击下拉列表中的项目时，可能会调用webservice。如果调用了webservice，那么可能会再次加载您的页面？我不知道它不起作用的确切原因。您必须检查调用服务时发生的服务行为。
答案 1 :(得分：0)
我基本上重建了我的模态弹出窗口并更新了面板
<asp:Panel ID="pnlEditPopup" runat="server" CssClass="modalPopup">
<asp:UpdatePanel ID="UpdatePanel2" runat="server">
<ContentTemplate>
<asp:Panel ID="pnlEditPopupContent" runat="server">
<div style="padding: 10px; border: 3px solid black; background-color: White; color: Black;">
<table cellpadding="0" cellspacing="4" border="0">
<tr>
<td class="name">Category:</td>
<td class="value">
<asp:DropDownList id="ddCat" runat="server">
<asp:listitem value="">No Selection</asp:listitem>
<asp:listitem value="Action">Action</asp:listitem>
<asp:listitem value="Worksite">Worksite</asp:listitem>
<asp:listitem value="Human Factors">Human Factors</asp:listitem>
<asp:listitem value="System Factors">System Factors</asp:listitem>
</asp:DropDownList>
</td>
</tr>
<tr>
<td class="name">Type:</td>
<td class="value">
<asp:DropDownList id="ddType" runat="server" />
<ajaxToolkit:CascadingDropDown ID="ccType" runat="server"
TargetControlID="ddType"
ParentControlID="ddCat"
PromptText="No Selection"
LoadingText="Please Wait..."
ServicePath="~/2012/IrSubmitWebService.asmx"
ServiceMethod="getTypeofAction"
Category="Other"
/>
</td>
</tr>
<tr>
<td class="name">Factor:</td>
<td class="value">
<asp:DropDownList id="ddfactor" runat="server" />
<ajaxToolkit:CascadingDropDown ID="ccFactor" runat="server"
TargetControlID="ddfactor"
ParentControlID="ddType"
PromptText="No Selection"
LoadingText="Please Wait..."
ServicePath="~/2012/IrSubmitWebService.asmx"
ServiceMethod="getFactor"
Category="Other"
/>
</td>
</tr>
<tr>
<td>
Justification:
<asp:Label ID="factorID" runat="server" Visible="false"></asp:Label>
</td>
<td>
<asp:TextBox ID="txtJustification" runat="server" ForeColor="DimGray" Height="100px"
Style="font-family: Tahoma; font-size: small" TabIndex="56" TextMode="MultiLine"
ToolTip="Provide a justification for this factor." Width="300px" Font-Names="Tahoma"
Font-Size="Small"></asp:TextBox>
</td>
</tr>
<tr>
<td>
Factor ID<br />
and Description:
</td>
<td>
<asp:Label ID="factor_id_Desc" runat="server" Width="300px" Font-Names="Tahoma" Font-Size="Small"
ForeColor="DimGray" TabIndex="56"></asp:Label>
<cc1:DynamicPopulateExtender ID="DynamicPopulateExtender1" runat="server"
Enabled="True" TargetControlID="factor_id_Desc" BehaviorID="dp1" ServiceMethod="getFactorID"
ServicePath="~/2012/IrSubmitWebService.asmx">
</cc1:DynamicPopulateExtender>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:Button ID="btnOkEditPopup" runat="server" Text="Ok" CssClass="button"/>
<span style="margin-left:10px"><asp:button id="btnCancelEditPopup" runat="server" text="Cancel" CssClass="button"/></span>
</td>
</tr>
</table>
</div>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
<ajaxToolkit:ModalPopupExtender ID="mpeEdit" runat="server"
TargetControlID="btnOpenEditPopup"
PopupControlID="pnlEditPopup"
/>
修正了我的问题。当我问这个问题但是我能够解决它时，我仍然不知道它为什么不起作用。感谢所有为我调查过的人。