Question

代码不会将值保存到Musician实体。我正在使用保存SelectList的ViewBag并显示数据库中的内容，但在保存时，对于调试时的musician.PrimaryInstrument字段，它为null。剃刀：

lazy var currentArticle: Article = {
    let article = Article()
    //any other initialization you need
    return article
}()

控制器：

<td>                           
  @Html.LabelFor(model => model.PrimaryInstrument, htmlAttributes: new { @class = "control-label col-md-2" })
</td>
<td>
  @Html.DropDownList("InstrumentList")
</td>

仪器型号：

public ActionResult Edit(string id)
{
  if (id == null)
  {
    return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
  }
  Musician musician = (Musician)db.Contractor.Find(id);
  if (musician == null)
  {
    return HttpNotFound();
  }
  ViewBag.InstrumentList = new SelectList(db.Instrument, "ID", "Name");
  return View(musician);
}

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit(Musician musician, HttpPostedFileBase image)
{
  if(ModelState.IsValid)
  {
    if (image != null)
    {
      UploadImage(musician, image);
    }
    musician.YearsOfExperience = Convert.ToInt16(Request["yearsOfExperience"]);
    musician.CreateDate = DateTime.Now;
    musician.NextDateAvailable = DateTime.Now;
    db.Entry(musician).State = EntityState.Modified;
    db.SaveChanges(); 
    return RedirectToAction("Profile");
  }
  return View();
}

}

音乐家模特：

    public class Instrument
{
    public int ID { get; set; }
    public string Name { get; set; }


    public ICollection<Musician> Musician { get; set; }
}

Answer 1

您当前未将所选工具绑定到属性PrimaryInstrument。你的助手应该是

@Html.DropDownListFor(m => m.PrimaryInstrument, (SelectList)ViewBag.InstrumentList)

请注意，这会将ID的{{1}}属性绑定到属性Instrument

另请注意，如果PrimaryInstrument无效，您还需要在致电ModelState之前重新分配ViewBag.InstrumentList媒体资源ViewBag.InstrumentList = new SelectList(db.Instrument, "ID", "Name");

保存模式的下拉列表不起作用

1 个答案: