javascript - 如何检查Jquery多选下拉列表中的选项？

我无法从jQuery多选下拉列表中检查一个选项
即使能够在多选列表中找到该选项。
请告诉我我所缺少的。谢谢！！

//this is my multi-select dropdown<br/>
$("#ddlCountries").multiselect();

var country = "USA";

//I tried below, but it did not work
//$("#ddlCountries").multiselect("widget").find(":checkbox[value='" + country + "']").attr("checked", true);

  @ Bhavin的回应：
  我照你说的做了，仍然没有得到预期的结果。请看下面。

$(document).ready(function () {
    $("#ddlCountries").multiselect();
    $("#ddlCountries").multiselect('uncheckAll');
}


function ddlRole_OnChange(){
    //client object of ddlRoles combobox
    var roles = $(this).data('tComboBox');
    //selected item from ddlRoles
    var selectedRole = roles.text();

    if (selectedRole.toLowerCase() === "admin"){
        //custom yes/no dialog box (first param is Title, second param is Question, third param is callback function)
        YesNoJqueryDailogBox('Admin Configuration:', 'Need Admin Role ?', 'selectForAdminRole');
    }
}

function selectForAdminRole(){

    $(document).ready(function (){
        $("#ddlCountries").multiselect();
        $("#ddlCountries").multiselect('uncheckAll');
        var country = "USA";
        $("#ddlCountries").multiselect("widget").find(":checkbox[value='" + country + "']").prop('checked', true);
    });
}

  回复@ Ziv Weissman
  MVC视图（.cshtml）

<tr>
    <td align="left" valign="middle" width="30%">
        @if (ViewBag.Roles != null)
        {
         @(
            Html.Telerik().ComboBox().Name("ddlRole") @*server-side combobox name*@
           .BindTo((IEnumerable<SelectListItem>)ViewBag.Roles) @*server-side ddlRole binding in page load*@
           .ClientEvents(events => events.OnChange("ddlRole_OnChange")) @*server-side ddlRole change event*@
          )
        }
    </td>
 </tr>

 <tr>
     <td align="left" valign="middle" width="15%" height="40" >
        Countries <span class="mandatory">*</span>
     </td>
     <td align="left" valign="middle" width="20%" >
        @if (ViewBag.Countries != null)
        {
           @*server-side ddlCountries dropdown binding in page load*@
           @Html.DropDownList("ddlCountries", (IEnumerable<SelectListItem>)ViewBag.Countries)
        }
     </td>
 </tr>

  已解决：检查选项后刷新ddlCountries下拉列表解决了该问题。

var countries= $("#ddlCountries").multiselect('uncheckAll');
countries.children('option').each(function (){

    var countryNameText = $(this).text();
    if (countryNameText == "admin"){
            $(this).attr('selected', 'selected');
    }
});
$("#ddlCountries").multiselect("refresh");

  谢谢大家！

最佳答案

您必须刷新multiSelect，以及为什么要添加$（document）.ready并选择For Admin Role函数

       $("#ddlCountries").find("option[value=" + ce + "]").prop("selected", true)
        $("#ddlCountries").multiselect("refresh")

你可以用这个

     $("#ddlCountries").val("USA");
      $("#ddlCountries").multiselect("refresh")

关于javascript - 如何检查Jquery多选下拉列表中的选项？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/34051372/