javascript - 使用下拉列表中选定的值更新 HTML.HiddenFor 值

Question

我有一个简单的销售信息形式，用户可以编辑评论和原因，然后使用 SaveChanges() 函数将数据提交回数据库。我需要更新包含 ID 号的字段。我有一个简单的下拉列表(由viewbag填充)，当用户进行更改时，我想更新hiddenfor字段中的ID号，以便可以在保存时将其发回。我的代码如下:

编辑器模板

   <tr>
@Html.HiddenFor(modelItem => modelItem.ID)
@Html.HiddenFor(modelItem => modelItem.tblTaggingGroupID)
@Html.HiddenFor(modelItem => modelItem.FinYear)
@Html.HiddenFor(modelItem => modelItem.FinWeek)
@Html.HiddenFor(modelItem => modelItem.WeekDay)
@Html.HiddenFor(modelItem => modelItem.Segment)
@Html.HiddenFor(modelItem => modelItem.NetSales)
@Html.HiddenFor(modelItem => modelItem.SwellSales)
@Html.HiddenFor(modelItem => modelItem.SpikeSales)
@Html.HiddenFor(modelItem => modelItem.BaseSales)
@Html.HiddenFor(modelItem => modelItem.tblTaggingReasonID)
<td>
    @switch (Model.WeekDay)
    {
        case 1:
            @:Sunday
            break;
        case 2:
            @:Monday
            break;
        case 3:
            @:Tuesday
            break;
        case 4:
            @:Wednesday
            break;
        case 5:
            @:Thursday
            break;
        case 6:
            @:Friday
            break;
        case 7:
            @:Saturday
            break;
        default:
            break;
    }
</td>
<td>
    @Html.DisplayFor(modelItem => modelItem.Segment)
</td>

<td>
    @Html.DisplayFor(modelItem => modelItem.NetSales)
</td>
<td>
    @Html.DisplayFor(modelItem => modelItem.SwellSales)
</td>
<td>
    @Html.DisplayFor(modelItem => modelItem.SpikeSales)
</td>
<td>
    @switch (Model.Recurring)
    {
        case true:
            Model.Recurring.ToString();
            break;
        case false:
            Model.Recurring.ToString();
            break;
        default:
            break;
    }
    @Html.EditorFor(modelItem => modelItem.Recurring)
</td>

<td>@Html.DropDownListFor(modelItem => modelItem.tblTaggingReasonID, (SelectList)ViewBag.Reasons, "Please Select")</td>
<td>
    @Html.EditorFor(modelItem => modelItem.Comment, new { @class = "Commenttxt" })
</td>

Controller :

        public ActionResult Index()
    {
        var SelectedID = Convert.ToInt32(Session["_SessionSelectGroupID"]);
        var SelectedYear = Convert.ToInt32(Session["_SessionSelectFinYear"]);
        var SelectedWeek = Convert.ToInt32(Session["_SessionSelectFinWeek"]);
        var tblTaggingGroupInstances = db.tblTaggingGroupInstances.Include(t => t.tblTaggingGroup);

         ViewBag.Reasons = new SelectList(db.tblTaggingReasons,"ID","UpliftReason");

        return View(tblTaggingGroupInstances.Where(t => t.tblTaggingGroupID == SelectedID && t.FinYear == SelectedYear && t.FinWeek == SelectedWeek).ToList());
    }
    [HttpPost]
    public ActionResult Index(List<tblTaggingGroupInstance> model)
    {
        foreach (var record in model)
        {
            db.Entry(record).State = EntityState.Modified;
        }
        db.SaveChanges();
        return RedirectToAction("Details");
    }

我假设这可以通过一些简单的 JQuery 或 Javascript 来完成，但是到目前为止我尝试过的所有内容都失败了？

Answer 1

无需使用 JavaScript 来更新隐藏的输入。相反，只需直接绑定(bind)到属性

@Html.DropDownList(m => m.tblTaggingReasonID, (SelectList)ViewBag.Reasons, "Please Select")

并从 View 中删除隐藏的输入。