复杂类型EF6 MVC5的修改清单

本文介绍了复杂类型EF6 MVC5的修改清单的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

假设我有以下几点：

public class Employee
    {
        public int EmployeeID { get; set; }
        public string FirstName { get; set; }
        public virtual List<LastName> LastName { get; set; }
    }

 public class LastName
    {
        public int LastNameID { get; set; }
        public new string Value1 { get; set; }
    }

和我有一个索引页，其中型号为员工具有以下列表：

and I have an index page where the model is a list of employees with the following:

@foreach (var item in Model) {
//link to Edit page where I can modify the last names in the list
@Html.ActionLink(item.LastName[someIndex], "Edit", new { id = item.EmployeeID })

和控制器我有

public ActionResult Edit(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Employee employee = db.Employees.Find(id);
            if (employee == null)
            {
                return HttpNotFound();
            }
            return View(employee);
        }

        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit(Employee employee)
        {
            if (ModelState.IsValid)
            {
               //EXCEPTION HERE -
                db.Entry(employee).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            return View(employee);
        }

和一个像这样的编辑视图

and an edit view like this

@model Testing123.Models.Employee

@{
    ViewBag.Title = "LastName";
}

<h2>Last Names</h2>

@using (Html.BeginForm())
{
    @Html.AntiForgeryToken()

        @Html.ValidationSummary(true, "", new { @class = "text-danger" })

        @for (int i = 0; i < Model.LastName.Count; i ++)
                {
                    @Html.TextBoxFor(m => m.LastName[i].Value1)

                   //ADDED HIDDEN FOR HERE**** Throwing new exception, see below
                    @Html.HiddenFor(m => m.LastName[i].LastNameID)


        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Save" class="btn btn-default" />
            </div>
        </div>
}

当我提出这个编辑表单，它给了我一个例外：

When I submit this edit form, it gives me an exception :

附加型Testing123.Models.LastName的实体失败，因为同类型的另一实体已经有相同的主键值。这可以用'附加'方法或设置实体'不变'或'修改'，如果图中的任何实体有冲突的关键值的状态时发生。这可能是因为一些实体是新的，但尚未收到数据库生成的键值。在这种情况下使用添加方法或添加实体状态跟踪图，然后设置非新的实体，以不变或修改适当的状态

Attaching an entity of type 'Testing123.Models.LastName' failed because another entity of the same type already has the same primary key value. This can happen when using the 'Attach' method or setting the state of an entity to 'Unchanged' or 'Modified' if any entities in the graph have conflicting key values. This may be because some entities are new and have not yet received database-generated key values. In this case use the 'Add' method or the 'Added' entity state to track the graph and then set the state of non-new entities to 'Unchanged' or 'Modified' as appropriate

这是修改姓氏复杂类型对象的列表的正确方法？
这意味着，如果有4个姓氏已经和我进入这个观点，与文本框，每个姓氏显示在一个文本框，我在文本框中更改值，将本次更新的形式提交姓氏？

Is this the correct way of modifying the List of LastName complex type object?meaning, If have 4 last names already, and I enter this view, with the text boxes, and each last name is displayed in a text box, and I change the value in the text box, will this update the last names on form submitting?

修改的

EDIT

添加HiddenFor帮手后，我得到了以下异常现在db.saveChanges

After adding the HiddenFor helper, I'm getting the following exception now on db.saveChanges

商店更新，插入或删除语句影响的行（0）的一个意想不到的数量。实体可能已被修改或删除，因为实体被装。刷新ObjectStateManager条目。

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.

the

复杂类型EF6 MVC5的修改清单

问题描述

推荐答案