无法遍历选择列表中的选项

Question

我有这个选择列表，如下：-

<input type="text" value="Departmental Folder Structure Clean up" maxlength="255" id="Title_fa564e0f-0c70-4ab9-b863-0177e6ddd247_$TextField" title="Title Required Field" style="ime-mode : " class="ms-long ms-spellcheck-true" disabled="disabled">
<select id="ProjectDependantProjectsLookup_b60c7117-fab9-43ec-8c10-4e714969dd20_SelectCandidate" multiple="multiple" title="Active Dependant Projects possible values" style="width: 300px; height: 125px; overflow: scroll;">
<option value="68" title=" .......Laptop/PC replacement Project"> ... Laptop/PC replacement Project</option>
<option value="83" title="3.....Deployment ">... Deployment </option>
<option value="108" title=".....sion">...g Session</option></select>

现在我要删除平铺字段具有标题=的选项，因此我尝试了此操作：-

var titlevalue = $('input[id^="Title_"]').val();
var currentprojecttitle = $($("[id^=ProjectDependantProjectsLookup_][id$=_SelectCandidate]")[0]);
for (var i=0; i<currentprojecttitle.length; i++) {
   if (currentprojecttitle.options[i].value == titlevalue)
      currentprojecttitle.remove(i);
}

但我收到此错误：-

未捕获的类型错误：无法读取未定义的'0'属性

尽管在我的情况下，$($("[id^=ProjectDependantProjectsLookup_][id$=_SelectCandidate]")[0])正确地引用了选择列表，因为当我运行此$($("[id^=ProjectDependantProjectsLookup_][id$=_SelectCandidate]")[0]).css('width','300px');时，它会增加宽度。

Answer 1

我认为设置var currentprojecttitle = $("[id^=ProjectDependantProjectsLookup_][id$=_SelectCandidate]")[0];更简单。在代码中，将其包装到jquery变量中，然后将其用作javascript变量。您可以看到一个演示here。我在Deployment选项中添加了相应的类，然后将其删除。

Answer 2

问题是您正在处理select的jQuery元素。您必须这样做：

var titlevalue = $('input[id^="Title_"]').val();
var currentprojecttitle = $($("[id^=ProjectDependantProjectsLookup_][id$=_SelectCandidate]")[0]);
for (var i=0; i<currentprojecttitle.length; i++) {
   if (currentprojecttitle[0].options[i].value == titlevalue)//Selecting the first element of the jQuery collection
      currentprojecttitle[0].remove(i);
}