将ID从一个视图传递到另一个视图并将其存储在另一个表中

Question

我有一个创建页面，用于为用户添加节日和页面，以便为该节日创建活动。我试图传递节日ID并将其存储在我的事件表中。它被捕获在创建页面的帖子后面。这是代码：

控制器：

[HttpGet]
    public ActionResult Create2(int festID)
    {
        EventsVM events = new EventsVM { festivalID = festID };

        events.eType = db.EType.ToDictionary(p => p.ID, q => q.EType);
        events.eType.Add(-1, "----- Add New Event Type -----");

        events.eventsDate = DateTime.Now;
        events.startTime = DateTime.Now;
        events.endTime = DateTime.Now;

        return View(events);
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create2(EventsVM model)
    {
        if (ModelState.IsValid != true)
        {
            if (model.selectedEType != -1)
            {
                //db.save stuff from create.
                Events Newevent = new Events();
                Newevent.EndTime = model.endTime;
                Newevent.StartTime = model.startTime;
                Newevent.EventsDate = model.eventsDate = DateTime.Now;
                Newevent.EventsName = model.EventsName;
                Newevent.EType = db.EType.Where(p => p.ID == model.selectedEType).Single();
                Newevent.Location = model.Location;
                //Caught here!!!
                Newevent.FestivalID = model.festivalID;

                db.Events.Add(Newevent);
                db.SaveChanges();
                return RedirectToAction("Details", "Festival", new { id = model.festivalID });
                //return RedirectToAction("Index", "Festival");
                //return RedirectToAction("Index", "Events");
                //String test = "test3";
            }
            ModelState.AddModelError("", "No Event Type Picked");
        }

        model.eType = db.EType.ToDictionary(p => p.ID, q => q.EType);
        model.eType.Add(-1, "----- Add New Event Type -----");
        model.eventsDate = DateTime.Now;
        model.startTime = DateTime.Now;
        model.endTime = DateTime.Now;

        return View(model);
    }

我必须在所选节日ID

的详细信息页面上“保存”节日ID

Details.cshtml - 节日

 <div>
<h3>Details for Festival: @Model.FestivalName.ToString()</h3>
</div>
<hr />
<div class="table-responsive">
<!--<div class="table">-->
    <table class="table">
        <tr>
            <th>
                Festival Name
            </th>
            <th>
                Start Date
            </th>
            <th>
                End Date
            </th>
            <th>
                Town
            </th>
            <th>
                County
            </th>
            <th>
                Festival Type
            </th>
            <th>
                Options
            </th>
        </tr>
        <tr>
            <td>
                @Html.DisplayFor(model => model.FestivalName)
            </td>
            <td>
                @Html.DisplayFor(model => model.StartDate)
            </td>
            <td>
                @Html.DisplayFor(model => model.EndDate)
            </td>
            <td>
                @Html.DisplayFor(model => model.FestivalTown.Name)
            </td>
            <td>
                @Html.DisplayFor(model => model.FestivalCounty.Name)
            </td>
            <td>
                @Html.DisplayFor(model => model.FType.FType)
            </td>
            <td>
                <div class="btn-group">
                    @*                        <button class="btn btn-info btn-sm dropdown-toggle" type="button" data-toggle="dropdown">Options</button>*@
                    <button type="button" class="btn btn-info btn-sm dropdown-toggle" data-toggle="dropdown">
                        <span class="caret"></span>
                    </button>
                    <ul class="dropdown-menu">
                        <li role="presentation" class="dropdown-header">Festival</li>
                        <li>@Html.ActionLink("Edit", "Edit2", new { id = Model.FestivalId })</li>
                        <li>@Html.ActionLink("Back to List", "Index")</li>
                    </ul>
                </div>
            </td>
        </tr>
    </table>
</div>
@if (Model.Events != null)
{
    <center><div class="well well-sm" style="width:400px">@Model.FestivalName.ToString() has @Model.Events.Count() Events</div></center>
    @Html.ActionLink("Add Event", "Create2", "Events", new { festID = Model.FestivalId }, new { @class = "btn btn-primary"})
    <br />
    <br />
    <!--<div class="table-responsive">-->
    <div class="table">
        <table class="table table-striped">
            <tr>
                <th>Events Name
                </th>
                <th>Events Date
                </th>
                <th>Start Time
                </th>
                <th>End Time
                </th>
                <th>Options
                </th>
            </tr>

            @foreach (var e in Model.Events)
            {
                <tr>
                    <td>
                        @Html.DisplayFor(modelItem => e.EventsName)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => e.EventsDate)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => e.StartTime)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => e.EndTime)
                    </td>
                    <td>
                        <div class="btn-group">
                            <button type="button" class="btn btn-success btn-sm dropdown-toggle" data-toggle="dropdown">
                                <span class="caret"></span>
                            </button>
                            <ul class="dropdown-menu">
                                <li role="presentation" class="dropdown-header">Event</li>
                                <li role="presentation" class="divider"></li>
                                <li>@Html.ActionLink("Edit", "Edit2", "Events", new { id = e.ID }, null)</li>
                                <li>@Html.ActionLink("Details", "Details", "Events", new { id = e.ID }, null)</li>
                                <li>@Html.ActionLink("Delete", "Delete", "Events", new { id = e.ID }, null)</li>
                            </ul>
                        </div>
                    </td>
                </tr>
            }

        </table>
    </div>  
}

我得到的错误是当它回发时，链接中的id变为0，因此它不保存id。关于如何解决这个问题的任何ID？

Answer 1

id为0，因为您传递的是model.ID而不是EF在SaveChanges之后生成的实体ID（将更改传播到数据库中）并添加到ObjectSet。因此，ID会自动为您填写。将您的代码更改为此。

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create2(EventsVM model)
{
    if (ModelState.IsValid != true)
    {
        if (model.selectedEType != -1)
        {
            //db.save stuff from create.
            Events Newevent = new Events();
            Newevent.EndTime = model.endTime;
            Newevent.StartTime = model.startTime;
            Newevent.EventsDate = model.eventsDate = DateTime.Now;
            Newevent.EventsName = model.EventsName;
            Newevent.EType = db.EType.Where(p => p.ID == model.selectedEType).Single();
            Newevent.Location = model.Location;
            //Caught here!!!
            Newevent.FestivalID = model.festivalID;

            db.Events.Add(Newevent);
            db.SaveChanges();
            //Change the model.festivalID to Newevent.FestivalID
            return RedirectToAction("Details", "Festival", new { id = Newevent.FestivalID });
            //return RedirectToAction("Index", "Festival");
            //return RedirectToAction("Index", "Events");
            //String test = "test3";
        }
        ModelState.AddModelError("", "No Event Type Picked");
    }

    model.eType = db.EType.ToDictionary(p => p.ID, q => q.EType);
    model.eType.Add(-1, "----- Add New Event Type -----");
    model.eventsDate = DateTime.Now;
    model.startTime = DateTime.Now;
    model.endTime = DateTime.Now;

    return View(model);
}

Answer 2

以下是@Overmachine的答案

    [HttpGet]
    public ActionResult Create2(int festID)
    {
        EventsVM events = new EventsVM { festivalID = festID };

        events.eType = db.EType.ToDictionary(p => p.ID, q => q.EType);
        events.eType.Add(-1, "----- Add New Event Type -----");

        events.eventsDate = DateTime.Now;
        events.startTime = DateTime.Now;
        events.endTime = DateTime.Now;

        return View(events);
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create2(EventsVM model, int festID)
    {
        if (ModelState.IsValid != true)
        {
            if (model.selectedEType != -1)
            {
                //db.save stuff from create.
                Events Newevent = new Events();
                Newevent.EndTime = model.endTime;
                Newevent.StartTime = model.startTime;
                Newevent.EventsDate = model.eventsDate = DateTime.Now;
                Newevent.EventsName = model.EventsName;
                Newevent.EType = db.EType.Where(p => p.ID == model.selectedEType).Single();
                Newevent.Location = model.Location;
                //Caught here!!!
                Newevent.FestivalID = model.festivalID = festID;

                db.Events.Add(Newevent);
                db.SaveChanges();
                //Change the model.festivalID to Newevent.FestivalID
                return RedirectToAction("Details", "Festival", new { id = Newevent.FestivalID });
                //return RedirectToAction("Index", "Festival");
                //return RedirectToAction("Index", "Events");
                //String test = "test3";
            }
            ModelState.AddModelError("", "No Event Type Picked");
        }

        model.eType = db.EType.ToDictionary(p => p.ID, q => q.EType);
        model.eType.Add(-1, "----- Add New Event Type -----");
        model.eventsDate = DateTime.Now;
        model.startTime = DateTime.Now;
        model.endTime = DateTime.Now;

        return View(model);
    }