在MVC中设置多选下拉菜单的选定值

<select id="myDropdown" multiple>
    <option value="option1">选项1</option>
    <option value="option2">选项2</option>
    <option value="option3">选项3</option>
    <option value="option4">选项4</option>
</select>

public ActionResult MyAction()
{
    // 获取需要设置为选定的值
    List<string> selectedValues = new List<string> { "option2", "option4" };

    // 将选定值传递给视图
    ViewBag.SelectedValues = selectedValues;

    return View();
}

<script>
    $(document).ready(function() {
        // 获取传递的选定值
        var selectedValues = @Html.Raw(Json.Encode(ViewBag.SelectedValues));

        // 设置多选下拉菜单的选定值
        $("#myDropdown").val(selectedValues);
    });
</script>