jquery - MVC4 Razor 中的 Dropdownlist SelectedItemChanged 事件？

Question

MVC4中是否有像onChange等可用于Dropdownlist的事件？我们是否必须使用 Javascript/jQuery 才能进行一些操作，例如 DropwowlistSelectedItemChanged 等？或者有一种方法只使用 Razor 或 MVC4 功能？

另一方面，您能否给我一些示例，如何根据下拉列表选定值检索数据并使用该数据更改标签文本？例如，当从下拉列表中选择城市时，我想使用所选城市 ID 从数据库中获取地址数据，然后在标签上显示检索到的地址。如果您能向我澄清上述问题并给我一个实现此目标的示例，我将不胜感激。

Controller :

private void PopulateMeetingsDropDownList(object selectedMeetings = null)
    {
        var meetingsQuery = repository.Meetings
            .Join(repository.Cities, m => m.MeetingCityId, c => c.CityID,
                (m, c) => new
                {
                    CityID = c.CityID,
                    CityName = c.CityName,
                    MeetingDate = m.MeetingStartDate
                }
            )
            .OrderBy(x => x.CityID)
            .AsEnumerable()
            .Select(
                i => new
                {
                    CityID = i.CityID,
                    DisplayValue = string.Format(
                        "{0} ({1:dd MMMM yyyy})",
                        i.CityName, i.MeetingDate)
                }
            ).ToList();
        ViewData["MeetingId"] = new SelectList(meetingsQuery, "CityID", "DisplayValue", selectedMeetings);
    }

查看:

<label>Meeting</label>
@Html.DropDownListFor(m => m.MeetingId, ViewData["MeetingId"] as SelectList,"---- Select ----", new { name = "meetingId", id = "meetingId"}) 

Answer 1

试试这个，

@Html.DropDownListFor(model => model.MyProp, (SelectList)ViewBag.ListItems, new { @id = "MyId", onchange = "MyFunction()" })

<script type="text/javascript">
    function MyFunction() {
        alert('Changed');
        $('#YourLabelId').val('ReplaceWithThisValue');
    }
</script>

或者这个

@Html.DropDownListFor(model => model.MyProp, (SelectList)ViewBag.ListItems, new { @id = "MyId"})

<script type="text/javascript">
   $('#MyId').change(function(){
        alert('Changed');
        $('#YourLabelId').val('ReplaceWithThisValue');
    });
</script>