在ASP.NET核心中使用Ajax更新下拉列表

<select id="myDropdown" name="myDropdown"></select>

<script>
    $(document).ready(function () {
        $.ajax({
            url: '/Controller/Action', // 替换为你的控制器和动作方法的URL
            type: 'GET',
            success: function (data) {
                var dropdown = $('#myDropdown');
                dropdown.empty();
                $.each(data, function (index, item) {
                    dropdown.append($('<option></option>').val(item.value).text(item.text));
                });
            }
        });
    });
</script>

[HttpGet]
public IActionResult Action()
{
    var data = new List<SelectListItem>
    {
        new SelectListItem { Value = "1", Text = "Option 1" },
        new SelectListItem { Value = "2", Text = "Option 2" },
        new SelectListItem { Value = "3", Text = "Option 3" }
    };

    return Json(data);
}