无法获取未定义或空引用的属性“单击” [英] Unable to get property 'click' of undefined or null reference

问题描述

使用上一个问题中的答案，ModalPopupExtender：弹出窗口关闭文本框文件的TextChanged方法后，我能够让弹出窗口按照预期的方式工作，作为一个独立的表单，包括添加第三个按钮到模态弹出窗口：

< asp：按钮ID =btnResetrunat =serverText =StandardOnClick =btnReset_Click/> 

但是当我添加相关代码现有网站时，我收到以下错误：



错误：无法获取属性点击未定义或空引用。



该网站使用母版页，模态弹出式面板位于两个面板中，所有面板都被包围选项卡面板上的更新面板。什么会阻止执行新按钮的onclick代码？还有另一种执行代码的方法吗？

我只有弹出窗口的Ok和Cancel按钮的javascript（没有用于重置）：
 
 <   script    类型  =  text / javascript  >  
函数onOk（）{
 document.getElementById（'btnOk'）。click（）; 
} 
 
函数onCancel（）{
 document.getElementById（'btnCancelRates'）。click（）; 
 
} 
 <   / script  >  
 
如何调用新按钮的onclick代码？

解决方案

找到解决方案。我删除了OnCancel的JS。从ModalPopupExtendedupdates中删除了CancelControlID和OnCancelScroipt，并使用OnClick事件进行重置和取消按钮。 Ok按钮使用JS，

 <   asp：Panel     ID   =  pnlCustCharge   宽度  =  275px    runat   =  server   样式  =  display：none >  
 <  表    style   =  margin-left：75px >  
 <   tr  >  
 <   td  >  
 <   asp：按钮    ID   =  OkButton    runat   =  server   文字  = 确定   样式  =  display：none  /  >  
 <   asp：按钮    ID   =  btnOk    runat   =  server   文本  = 确定  
   
                                             OnClick  < span class =code-keyword> =  btnOk_Click  /  >  
 <   / td  >  
 < ;   td     style  < span class =code-keyword> =  width：10px >  
 <   / td  >  
 <   td  >  
 <   asp：按钮    ID   =  CancelButton    runat   =  server   文本  = 重置  
   
                                   OnClick   =  btnCancelRates_Click    /  >  
 <   / td  >  
 <   td     style   =  width：10px >  
 <   / td  >  
 <   td  >  
 <   asp：按钮    ID   =  ResetButton    runat   = 服务器   文字  =  标准  
   
                                          < span class =code-attribute> OnClick   =  btnReset_Click    /  >  
 <   / td  >  
 <   / tr  >  
 < span class =code-keyword><   / table  >  
 <   / asp：Panel  >  
 <   br     /  >  
 <   cc1：ModalPopupExtender     ID   =  ModalPopupExtender1    runat   =  server    TargetControlID   =  btnCustCharges  
   
           PopupControlID   =  pnlCustCharge    BackgroundCssClass   =  modalBackground    DropShadow   =  true  
   
           EnableViewState   =  true    OkControlID   =  OkButton    OnOkScript   =  onOk（）  
   
           /   >  

Using the answer in my previous question, "ModalPopupExtender: Popup Closes After TextChanged Method of Textbox FIres", I was able to get the popup to work as intended as a stand-alone form including the addition of a third button to the "modal popup":

<asp:Button ID="btnReset" runat="server" Text="Standard" OnClick="btnReset_Click"/>

However when I add the relative code an existing website, I receive the following error:

"Error: Unable to get property 'click' of undefined or null reference".

The website uses a master page and the modal popup panel is within two panels, all of which is surrounded by an update panel on a tab panel. What would prevent execution of the onclick code of the new button? Is there another method to executing the code?

I only have javascript for the Ok and Cancel button of the popup (none for the Reset):

    <script type="text/javascript">
        function onOk() {
            document.getElementById('btnOk').click();
        }

        function onCancel() {
            document.getElementById('btnCancelRates').click();

        }
    </script>

How would I call the onclick code for the new button?

解决方案

Found the solution. I removed the JS for the OnCancel. removed the CancelControlID and OnCancelScroipt from the ModalPopupExtendedupdates, and used OnClick events for Reset and Cancel buttons. The Ok button uses the JS,

<asp:Panel ID="pnlCustCharge" Width="275px" runat="server" Style="display: none">
    <table style="margin-left: 75px">
        <tr>
            <td>
                <asp:Button ID="OkButton" runat="server" Text="OK" Style="display: none"/>
                <asp:Button ID="btnOk" runat="server" Text="OK"

                     OnClick="btnOk_Click"/>
            </td>
            <td style="width: 10px">
            </td>
            <td>
                <asp:Button ID="CancelButton" runat="server" Text="Reset"

                OnClick="btnCancelRates_Click" />
            </td>
            <td style="width: 10px">
            </td>
            <td>
                <asp:Button ID="ResetButton" runat="server" Text="Standard"

                    OnClick="btnReset_Click" />
            </td>
        </tr>
    </table>
</asp:Panel>
<br />
<cc1:ModalPopupExtender ID="ModalPopupExtender1" runat="server" TargetControlID="btnCustCharges"

    PopupControlID="pnlCustCharge" BackgroundCssClass="modalBackground" DropShadow="true"

    EnableViewState="true" OkControlID="OkButton" OnOkScript="onOk()"

    />

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