MVC 4樂觀併發異常

Question

面對這個issue（我想允許通過使用引導模式窗口編輯，我使用MVC4和實體框架），當我想保存我的更改時，我有此錯誤消息，因爲我使用的是模態窗口：

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries. 

這裏是我的操作：

[HttpGet] 
     public ActionResult EditPerson(long id) 
     { 
      var person = db.Persons.Single(p => p.Id_Person == id); 

      ViewBag.Id_ProductPackageCategory = new SelectList(db.ProductPackageCategories, "Id_ProductPackageCategory", "Name", person.Id_ProductPackageCategory); 

      return PartialView("_EditPerson", person); 
     } 

     [HttpPost] 
     public ActionResult EditPerson(Person person) 
     { 
      ViewBag.Id_ProductPackageCategory = new SelectList(db.ProductPackageCategories, "Id_ProductPackageCategory", "Name", person.Id_ProductPackageCategory); 

      if (ModelState.IsValid) 
      { 
       ModelStateDictionary errorDictionary = Validator.isValid(person); 

       if (errorDictionary.Count > 0) 
       { 
        ModelState.Merge(errorDictionary); 
        return View(person); 
       } 

       db.Persons.Attach(person); 
       db.ObjectStateManager.ChangeObjectState(person, EntityState.Modified); 
       db.SaveChanges(); 
       return View("Index"); 
      } 

      return View(person); 
     } 

我的部分觀點：

@model BuSIMaterial.Models.Person 

<div class="modal-header"> 
<button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button> 
    <h3 id="myModalLabel">Edit</h3> 
</div> 
<div> 

@using (Ajax.BeginForm("EditPerson", "Person", FormMethod.Post, 
        new AjaxOptions 
        { 
         InsertionMode = InsertionMode.Replace, 
         HttpMethod = "POST", 
         UpdateTargetId = "table" 
        })) 
{ 

    @Html.ValidationSummary() 
    @Html.AntiForgeryToken() 

    <div class="modal-body"> 
     <div class="editor-label"> 
      First name : 
     </div> 
     <div class="editor-field"> 
      @Html.TextBoxFor(model => model.FirstName, new { maxlength = 50 }) 
      @Html.ValidationMessageFor(model => model.FirstName) 
     </div> 
     <div class="editor-label"> 
      Last name : 
     </div> 
     <div class="editor-field"> 
      @Html.TextBoxFor(model => model.LastName, new { maxlength = 50 }) 
      @Html.ValidationMessageFor(model => model.LastName) 
     </div> 
     <div class="editor-label"> 
      National number : 
     </div> 
     <div class="editor-field"> 
      @Html.EditorFor(model => model.NumNat, new { maxlength = 11 }) 
      @Html.ValidationMessageFor(model => model.NumNat) 
     </div> 
     <div class="editor-label"> 
      Start date : 
     </div> 
     <div class="editor-field"> 
      @Html.TextBoxFor(model => model.StartDate, new { @class = "datepicker", @Value = Model.StartDate.ToString("yyyy/MM/dd") }) 
      @Html.ValidationMessageFor(model => model.StartDate) 
     </div> 
     <div class="editor-label"> 
      End date : 
     </div> 
     <div class="editor-field"> 
      @if (Model.EndDate.HasValue) 
      { 
       @Html.TextBoxFor(model => model.EndDate, new { @class = "datepicker", @Value = Model.EndDate.Value.ToString("yyyy/MM/dd") }) 
       @Html.ValidationMessageFor(model => model.EndDate) 
      } 
      else 
      { 
       @Html.TextBoxFor(model => model.EndDate, new { @class = "datepicker" }) 
       @Html.ValidationMessageFor(model => model.EndDate) 
      } 
     </div> 
     <div class="editor-label"> 
      Distance House - Work (km) : 
     </div> 
     <div class="editor-field"> 
      @Html.EditorFor(model => model.HouseToWorkKilometers) 
      @Html.ValidationMessageFor(model => model.HouseToWorkKilometers) 
     </div> 
     <div class="editor-label"> 
      Category : 
     </div> 
     <div class="editor-field"> 
      @Html.DropDownList("Id_ProductPackageCategory", "Choose one ...") 
      @Html.ValidationMessageFor(model => model.Id_ProductPackageCategory) <a href="../ProductPackageCategory/Create"> 
       Add a new category?</a> 
     </div> 
     <div class="editor-label"> 
      Upgrade? : 
     </div> 
     <div class="editor-field"> 
      @Html.EditorFor(model => model.Upgrade) 
      @Html.ValidationMessageFor(model => model.Upgrade) 
     </div> 
    </div> 
    <div class="modal-footer"> 
     <button class="btn btn-inverse" type="submit">Save</button> 
    </div> 
} 

關於發生了什麼的任何想法？

Answer 1

在你有模頭，體，尾的局部視圖試試這個第一，略高於@Html.ValidationSummary()，地點：

@Html.HiddenFor(model => model.PersonId) // or.Id whatever's in your model 

這在您的視圖，並設置模型ID即PK創建一個隱藏字段。