Question

我不明白为什么我的编辑页面无法在我的下拉列表中获取所选值。

我的创建功能工作正常，但我的编辑页面未在我的下拉列表中显示所选值。我试图通过使用Viewbags获取所选的值，如果我正在调试，则存在id。

这是我的Edit()

public ActionResult Edit(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        SeminarErstellen seminarerstellen = db.SeminarErstellen.Find(id);
        if (seminarerstellen == null)
        {
            return HttpNotFound();
        }
        ViewBag.FileUploadId = new SelectList(db.FileUpload, "FileUploadId", "FilePath", seminarerstellen.FileUploadId);
        ViewBag.LehrbeauftragterId = new SelectList(db.Lehrbeauftragter, "LehrbeauftragterId", "Vorname", seminarerstellen.LehrbeauftragterId);
        ViewBag.SeminarStatiId = new SelectList(db.SeminarStati, "SeminarStatiId", "StatusTyp", seminarerstellen.SeminarStatiId);
        ViewBag.SeminarTypId = new SelectList(db.SeminarTyp, "SeminarTypId", "Seminarbezeichnung", seminarerstellen.SeminarTypId);
        return View(seminarerstellen);
    }

这是我的观点的DropdownList：问题是，它总是选择我的下拉列表的第一项而不是选择的......我希望你理解......

 <div class="form-group">
        @Html.LabelFor(model => model.SeminarTypId, "SeminarTypId", new { @class = "control-label col-md-2" })
        <div class="col-md-3">
            @* This Dropdown is selecting the right value but without Bootstrap!*@
            @*@Html.DropDownList("SeminarTypId", String.Empty)*@
            @* This line is selecting the wrong item, its selecting the first item of the list*@
            @Html.DropDownList("SeminarTypId", (SelectList)ViewBag.SeminarTypId,  new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model.SeminarTypId)
        </div>
</div>

Answer 1

删除您的混乱

......................

1. 引导程序类与DropDownList
2.问题是你的命名惯例

<强> 解决方案

问题出在您的ViewBag属性名称中。因为它与模型中的属性相同，所以不起作用。

YourCode

Controller

ViewBag.SeminarTypId = new SelectList(db.SeminarTyp, "SeminarTypId", minarbezeichnung",seminarerstellen.SeminarTypId);

View

@Html.DropDownList("SeminarTypId", (SelectList)ViewBag.SeminarTypId,  new { @class = "form-control" })

Modification

Controller

ViewBag.SeminarTypId123 = new SelectList(db.SeminarTyp, "SeminarTypId", minarbezeichnung",seminarerstellen.SeminarTypId);

View

@Html.DropDownList("SeminarTypId", (SelectList)ViewBag.SeminarTypId123,  new { @class = "form-control" })

Asp.net MVC5 Bootstrap：无法在编辑页面下拉列表中获取所选值

1 个答案: