实体框架持久性问题给出“ObjectStateManager 不包含引用类型对象的 ObjectStateEntry..”

Question

在我的数据库中：

PK CountryID int notnull
PK ServiceID int notnull
PK TaskID int notnull
PK TaskItemID int notnull
PK CorrespondentID int notnull
PK PreviousTask int notnull
   IsOnTimeline bit not null
   ..and 5 other nullable fields

我正在使用这个组合键来确保“ServiceSchedule”项的唯一性。 “Previoustask”字段是所有 PK 的串联，其想法是我可以构建从记录到记录相关的细粒度“ServiceSchedule”任务时间线。

上下文是：

UPEntities db = new UPEntities(); for all workings here (i.e. repository and db).

两个编辑控制器操作如下所示：

     public ActionResult Edit(int countryid,
                                int serviceid,
                                int taskid,
                                int taskitemid,
                                int correspondentid)
    {
        var t = (from s in repository.GetServiceSchedules()
                            where s.CountryID == countryid
                            where s.ServiceID == serviceid
                            where s.TaskID == taskid
                            where s.TaskItemID == taskitemid
                            where s.CorrespondentID == correspondentid
                            select s).First();

        return View(t);
    }



    [HttpPost]
    public ActionResult Edit(ServiceSchedule serviceToEdit)
    {

        var originalService = (from s in repository.GetServiceSchedules()
                               where s.CountryID == serviceToEdit.CountryID
                               where s.ServiceID == serviceToEdit.ServiceID
                               where s.TaskID == serviceToEdit.TaskID
                               where s.TaskItemID == serviceToEdit.TaskItemID
                               where s.CorrespondentID == serviceToEdit.CorrespondentID
                               select s).First();


       if (!ModelState.IsValid)

         return View(originalService);

         db.ApplyPropertyChanges(originalService.EntityKey.EntitySetName, serviceToEdit);        //Code throws exception here.......
         db.SaveChanges();

         return RedirectToAction("Index");           
    }

直到“db.ApplyPropertyChanges”行，一切似乎都工作正常，但我收到错误：

The ObjectStateManager does not contain an ObjectStateEntry with a reference to an object of type 'ProjectName.Models.ServiceSchedule'.

我注意到传递到编辑视图的模型包含来自相关表（例如，CountryID 中的国家/地区集合），但当模型从视图返回时，它仅包含“ServciceSchedule”表中的 PK ID，而不包含相关集合。

我目前正在尝试通过在这样的视图中创建hiddenfors来解决这个问题，但似乎仍然无法将完整的模型返回到控制器中：

<% using (Html.BeginForm())
   {%>
    <%= Html.ValidationSummary(true)%>

    <fieldset>
        <legend>Fields</legend>


        <div class="editor-label">
            <%= Html.HiddenFor(model => model.CountryID)%>
        </div>

        <div class="editor-label">
            <%= Html.HiddenFor(model => model.ServiceID)%>
        </div>

        <div class="editor-label">
            <%= Html.HiddenFor(model => model.TaskID)%>
        </div>

        <div class="editor-label">
            <%= Html.HiddenFor(model => model.TaskItemID)%>
        </div>

        <div class="editor-label">
            <%= Html.HiddenFor(model => model.CorrespondentID)%>
        </div>



         <div class="editor-label">
            <%= Html.HiddenFor(model => model.Services)%>
        </div>

        <div class="editor-label">
            <%= Html.HiddenFor(model => model.Tasks)%>
        </div>

        <div class="editor-label">
            <%= Html.HiddenFor(model => model.TaskItems)%>
        </div>

        <div class="editor-label">
            <%= Html.HiddenFor(model => model.Correspondents)%>
        </div>


        <div class="editor-field">
            <%= Html.TextBoxFor(model => model.PreviousTask)%>
            <%= Html.ValidationMessageFor(model => model.PreviousTask)%>
        </div>

        <div class="editor-label">
            <%= Html.LabelFor(model => model.Cost)%>
        </div>
        <div class="editor-field">
            <%= Html.TextBoxFor(model => model.Cost, String.Format("{0:F}", Model.Cost))%>
            <%= Html.ValidationMessageFor(model => model.Cost)%>
        </div>

        <div class="editor-label">
            <%= Html.LabelFor(model => model.ChargeOut)%>
        </div>
        <div class="editor-field">
            <%= Html.TextBoxFor(model => model.ChargeOut, String.Format("{0:F}", Model.ChargeOut))%>
            <%= Html.ValidationMessageFor(model => model.ChargeOut)%>
        </div>

        <div class="editor-label">
            <%= Html.LabelFor(model => model.DurationInDays)%>
        </div>
        <div class="editor-field">
            <%= Html.TextBoxFor(model => model.DurationInDays, String.Format("{0:F}", Model.DurationInDays))%>
            <%= Html.ValidationMessageFor(model => model.DurationInDays)%>
        </div>

        <div class="editor-label">
            <%= Html.LabelFor(model => model.JobSection)%>
        </div>
        <div class="editor-field">
            <%= Html.TextBoxFor(model => model.JobSection)%>
            <%= Html.ValidationMessageFor(model => model.JobSection)%>
        </div>

        <div class="editor-label">
            <%= Html.LabelFor(model => model.JobSectionGroup)%>
        </div>
        <div class="editor-field">
            <%= Html.TextBoxFor(model => model.JobSectionGroup)%>
            <%= Html.ValidationMessageFor(model => model.JobSectionGroup)%>
        </div>

        <p>
            <input type="submit" value="Save" />
        </p>
    </fieldset>

<% } %>

此外，GetServiceSchedules存储库看起来像这样：（

public class ServicesRepository
{
    UPEntities db = new UPEntities();


    public List<ServiceSchedule> GetServiceSchedules()
    {
        return db.ServiceScheduleSet.Include("Countries")
                                    .Include("Services")
                                    .Include("Tasks")
                                    .Include("TaskItems")
                                    .Include("Correspondents")
                                    .ToList();
    }

}

使用VS 2008，SQL 2008，MVC2）

任何人都可以让我知道一些更多建议的补救措施？