javascript 为什么我会收到“无法读取空值的属性‘点击’错误
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Why do I get a "Cannot read property 'click' of null error
提问by SearchForKnowledge
Inside the BODYtag:
里面的BODY标签：
<asp:Panel ID="nmSearch" CssClass="searchBox" runat="server" DefaultButton="HiddenSearchNM">
<input type="text" runat="server" value="" placeholder="Search" id="searchB" class="styledTB searchB floatLeft" />
<a href="JavaScript:void(0);" onclick="SearchNMClick();" title="Search" class="styledBtnSearch searchAnchor floatLeft defaultLinks">
<asp:Image ImageUrl="~/images/searchWhite.png" CssClass="searchImg" runat="server" ToolTip="Search" AlternateText="Search" />
</a>
<asp:ImageButton ID="HiddenSearchNM" runat="server" CssClass="hideContent" ClientIDMode="Static" />
</asp:Panel>
Inside the HEADtag:
里面的HEAD标签：
<script>
function SearchNMClick() {
document.getElementById('HiddenSearchNM').click();
}
</script>
I see the following error in the console:
我在控制台中看到以下错误：
Uncaught TypeError: Cannot read property 'click' of null
SearchNMClick
onclick
C# code behind which will fire off a search page from either Enteror click:
后面的 C# 代码将从以下任一位置触发搜索页面Enter或单击：
protected void HiddenSearchNM_Click(object sender, EventArgs e)
{
//MessageBox.Show("SEARCH NM");
strSMain = searchB.Value;
Response.Redirect("results.aspx?searchtext=" + strSMain +"&folderid=0&searchfor=all&orderby=title&orderdirection=ascending");
}
But when I hit enter while in the textbox or the button click, I get the error above.
但是当我在文本框中或单击按钮时按 Enter 键时，出现上述错误。
How do I resolve the error.
我该如何解决错误。
So weird, when I check the HTML source I see this (not sure why the ID is being changed):
太奇怪了，当我检查 HTML 源代码时，我看到了这个（不知道为什么要更改 ID）：
<input type="image" name="ctl00$CUSTOM_Area_Top$HiddenSearchNM" id="ctl00_CUSTOM_Area_Top_HiddenSearchNM" class="hideContent" ClientIDMode="Static" src="" onclick="javascript:WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions("ctl00$CUSTOM_Area_Top$HiddenSearchNM", "", true, "", "", false, false))" style="border-width:0px;" />
采纳答案by dario
You may change you JS function to:
您可以将 JS 函数更改为：
function SearchNMClick() {
document.getElementById('<%# HiddenSearchNM.ClientID %>').click();
}
回答by beautifulcoder
Use a Pagedirective to set static ids
使用Page指令设置静态 ID
<%@ Page ClientIDMode="static" %>
That should work with your id selector.
这应该适用于您的 id 选择器。
Also, check your rendered HTML for your ImageButton. If everything is setup correctly, it should preserve the ID.
此外，请检查您呈现的 HTML 以获取ImageButton. 如果一切设置正确，它应该保留ID.
