如何为 select2 至 jquery 的单个 select 下拉列表设置默认值

Question

我正在尝试设置 select2 个选项的默认 select 值，但它不起作用...有人可以帮助我吗？

这是我的控制器

 public ActionResult OrderAcceptanceDetails()
    {
        var res = Db.CustomerDetails.ToList();
        Session["cust"] = new SelectList(res, "CUSTCODE", "CUSTCODE");
        var yearlist = Db.Years.ToList();
        Session["year"] = new SelectList(yearlist, "Year1", "Year1");
        //var spresult = Db.Database.SqlQuery<OADetail>("Sp_OADetails_GetAll").ToList<OADetail>();
        return View();
    }

这是我的看法

<div class="col-md-3">
            <p>
                @Html.DropDownList("Year", Session["year"] as SelectList, "-- Select Year-- ", htmlAttributes: new { @class = "selectpicker", data_style = "select-with-transition" })
            </p>
        </div>

这是我的 javascript

 <script type="text/javascript">
    $(document).ready(function () {
            $("#Year").children("option:last-child").attr("selected",trues);
            })
            </script>

我想 select 来自 database.please 的下拉值的最后一个子项告诉我这怎么可能。？

Answer 1

为此尝试使用触发器属性： doc

$(document).ready(function () {
  $("#Year").select2({ width: '75px' });
  $("#Year").children("option:last-child").attr("selected", true).trigger('change');
})

<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.4/css/select2.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.4/js/select2.min.js"></script>

<select id="Year">
  <option value="2017">2017</option>
  <option value="2018">2018</option>
  <option value="2019">2019</option>
</select>

如何为 select2 至 jquery 的单个 select 下拉列表设置默认值

How to set default value for single select drop-down of select2 through jquery

javascript

jquery

asp.net-mvc-4

jquery-select2