으로 설정할 수 없습니다. 내보기에서 DropDownList는 올바른 필드를 표시하지만 "편집 또는 만들기"에서 필드를 선택하면 NULL로 저장/수정됩니다. 디버깅 할 때 새로운 값이 전송되지 않음을 알 수 있습니다.선택한 항목을 DropDownList에서 컨트롤러
@model Project_ASP_2012.Models.QuestionGroup
@{
ViewBag.Title = "Edit";
}
<h2>Edit</h2>
@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>QuestionGroup</legend>
@Html.HiddenFor(model => model.ID)
<div class="editor-label">
@Html.LabelFor(model => model.Description)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Description)
@Html.ValidationMessageFor(model => model.Description)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.SurveyID, "Survey")
</div>
<div class="editor-field">
@Html.DropDownList("Id", String.Empty)
@Html.ValidationMessageFor(model => model.SurveyID)
</div>
<p>
<input type="submit" value="Save" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}
모델 :
public class Survey : IEntity
{
[Key]
[Display(Name = "SurveyID")]
public int ID { get; set; }
[Required(ErrorMessage = "Survey title is required.")]
[Display(Name = "Survey Title")]
[MaxLength(20, ErrorMessage = "Title cannot be longer than 20 characters.")]
public string Title { get; set; }
[MaxLength(50, ErrorMessage = "Description cannot be longer than 50 characters.")]
public string Description { get; set; }
public virtual ICollection<QuestionGroup> QuestionGroups { get; set; }
}
public class QuestionGroup : IEntity
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ID { get; set; }
[MaxLength(50, ErrorMessage = "Description cannot be longer than 50 characters.")]
public string Description { get; set; }
[Display(Name = "SurveyID")]
public int? SurveyID { get; set; }
public virtual Survey Survey { get; set; }
}
컨트롤러 :보기에
public ActionResult Edit(int id)
{
QuestionGroup questiongroup = unitOfWork.QuestionGroupRepository.GetById(id);
if (questiongroup == null)
{
return HttpNotFound();
}
PopulateSurveysDropDownList(questiongroup.SurveyID);
return View(questiongroup);
}
//
// POST: /QuestionGroup/Edit/5
[HttpPost]
public ActionResult Edit(QuestionGroup questiongroup)
{
try
{
if (ModelState.IsValid)
{
unitOfWork.UoWContext.Entry(questiongroup).State = EntityState.Modified;
unitOfWork.SaveChanges();
return RedirectToAction("Index");
}
}
catch (DataException)
{
ModelState.AddModelError("", "Unable to save changes. Try again, and if the problem persists see your system administrator.");
}
PopulateSurveysDropDownList(questiongroup.SurveyID);
return View(questiongroup);
}
private void PopulateSurveysDropDownList(object selectedSurvey = null)
{
var surveyQuery = unitOfWork.SurveyRepository.Get(
orderBy: q => q.OrderBy(d => d.Title));
ViewBag.Id = new SelectList(surveyQuery, "Id", "Title", selectedSurvey);
}