MVC 4 乐观并发异常

Question

面对这个issue（我想允许使用引导模式窗口进行编辑，我正在使用 MVC4 和实体框架），当我想保存我的更改时，我收到了这个错误消息，因为我使用模态窗口：

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.

这是我的行动：

[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);
        }

我的部分观点：

@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>
}

知道发生了什么吗？

Answer 1

先试试这个，在局部视图的@Html.ValidationSummary()上方，你有模态的头部、主体和页脚，放置：

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

这会在您的视图中创建一个隐藏字段并设置模型 ID，即 PK。