Question

我有航班时刻表 - 航班列表的航班时刻表我只返回View并进行一些过滤和排序。

以下是我观点的一部分：

 @model IEnumerable<AirPortIS.Models.Flight>

    <div class="page-header">
        <h3>Flights</h3>
    </div>
    <div id="modDialog" class="modal fade">
        <div id="dialogContent" class="modal-dialog"></div>
    </div> 

    <table class="table-bordered table-condensed">
        <thead>
            <tr>
                <th>Flight №</th>
                <th>Departure</th>
                <th>Destination</th>
                <th>@Html.ActionLink("Day", "Schedule", new { sort = ViewBag.SortDay, company = ViewBag.FiltrC, destination = ViewBag.FiltrD })</th>
                <th>Departure Time</th>
                <th>Arrival Time</th>
                <th>Company</th>
                <th>@Html.ActionLink("Seats", "Schedule", new { sort = ViewBag.SortSeats, company = ViewBag.FiltrC, destination = ViewBag.FiltrD })</th>
                <th>@Html.ActionLink("Cost", "Schedule", new { sort = ViewBag.SortCost, company = ViewBag.FiltrC, destination = ViewBag.FiltrD })</th>
                <th>Book ticket</th>
            </tr>
        </thead>
        @foreach (var f in Model)
        {
            <tr>
                <td>@Html.ActionLink(f.FlightId.ToString(), "FlightDetails", new { id = f.FlightId }, new {@class = "flItem" } )</td>
                <td>@f.Departure</td>
                <td>@f.Destination</td>
                <td>@f.Day</td>
                <td>@f.DepartureTime</td>
                <td>@f.ArrivalTime</td>
                <td>@f.Company.Name</td>
                <td>@f.Seats</td>
                <td>@f.Cost</td>
                <td>@Html.ActionLink("Link for booking ticket")</td>
            </tr>
        }
    </table>

我需要通过单击“预订票证”按钮来实现这一点，用户正在获取一个页面，其中dropdownlist具有预设值FlightId。例如，我们有一个航班№1和一个链接“预订机票”，所以当用户进入预订机票页面时，他会获得一个预选值为“1”的下拉列表

这是我的票模型

public class Tickets
{
    public int Id { get; set; }
    public int TicketId { get; set; }
    public Flight Flight { get; set; }
    public string Seat {get;set; }
    public string Passenger { get; set; }
    public int Flightid { get; set; }
    public string Status { get; set; }
}

TicketsController的一部分：

 public class TicketsController : Controller
{
    private readonly AirportContext _db = new AirportContext();
    [Authorize]
    public ActionResult Tickets()
    {
        var ticket = _db.Tickets.Include(t => t.Flight);
        return View(ticket);
    }
    [HttpGet]
    public ActionResult BookTicket()
    {
        IEnumerable<SelectListItem> statusList = new SelectList(new List<string> { "Book", "Buy" });
        IEnumerable<SelectListItem> flights = new SelectList(_db.Flights.ToList(), "FlightId", "FlightId");
        ViewData["flights"] = flights;
        ViewData["statusList"] = statusList;
        return View();
    }
    [HttpPost]
    public ActionResult BookTicket(Tickets ticket)
    {
        IEnumerable<SelectListItem> statusList = new SelectList(new List<string> { "Book", "Buy" });
        IEnumerable<SelectListItem> flights = new SelectList(_db.Flights.ToList(), "FlightId", "FlightId");
        ViewData["flights"] = flights;
        ViewData["statusList"] = statusList;
        foreach (var c in _db.Tickets.ToList())
        {
            if ((_db.Tickets.ToList().Exists(x => c.TicketId == ticket.TicketId)) || (ticket.TicketId <= 0))
            {
                ModelState.AddModelError("TicketId", "Wrong ticket id");
            }
            if ((_db.Tickets.ToList().Exists(x => c.Seat == ticket.Seat)) && (_db.Tickets.ToList().Exists(x => c.Flightid == ticket.Flightid))
                && (_db.Tickets.ToList().Exists(x => c.TicketId == ticket.TicketId)))
            {
                ModelState.AddModelError("Seat", "The seat is unavailable");
            }
            if (_db.Tickets.ToList().Exists(x => c.Passenger == ticket.Passenger))
            {
               ModelState.AddModelError("Passenger", "The ticket has already bought");
            }
        }
        if (ModelState.IsValid)
        {
            _db.Tickets.Add(ticket);
            _db.SaveChanges();
            return RedirectToAction("Tickets");
        }
        else return View(ticket);
    }

我的BookTikcet观点：

@model AirPortIS.Models.Tickets

@{ 
ViewBag.Title = "Book ticket";
}
<h2>Book ticket:</h2>

<form class="form-inline" method="post">
    <div>
        @Html.ValidationSummary()
    </div>
    <div class="form-group col-md-2">
        Ticket №<br/>
        @Html.EditorFor(model => Model.TicketId)
    </div>
    <div class="form-group col-md-1">
       Flight №<br />
        @Html.DropDownListFor(model => Model.Flightid, ViewData["flights"] as IEnumerable<SelectListItem>)
    </div>
    <div class="form-group col-md-2">
        Место<br />
        @Html.EditorFor(model => Model.Seat)
    </div>
    <div class="form-group col-md-2">
        Passenger Name<br />
        @Html.EditorFor(model => Model.Passenger)
    </div>
    <div class="form-group col-md-2">
        Status<br />
        @Html.DropDownListFor(model => Model.Status, ViewData["statusList"] as IEnumerable<SelectListItem>)
    </div>
        <div>
            <input class="btn-success" type="submit" value="Book Ticket"/>
        </div>
</form>


<div>
<form method="get" action="Tickets">
    <button class="btn-danger" type="submit">Cancel</button>
</form>
</div>

我不知道该怎么做，所以上面的整个代码只是一个用于创建新票证的标准代码。我应该如何修改代码或添加一些东西（例如我们有一个航班№1和一个链接“预订机票”，所以当用户进入预订机票页面时，他获得一个预选值为“1”的下降列表，用于航班№对于FlightId，页面下拉列表中的2具有预选值“2”。希望我的问题清楚，对不起，如果写错了或不太清楚。

Answer 1

您需要将FlightId的值作为路由（或查询字符串）值传递给BookTicket方法。你的链接应该是

@Html.ActionLink("Book ticket", "BookTicket", new { id = f.FlightId })

并将方法修改为

[HttpGet]
public ActionResult BookTicket(int ID)
{
    ... // set you SelectLists as above
    // Initialize your model and set the Flightid property
    var model = new Tickets()
    {
        Flightid = ID
    };
    return View(model); // return the model to the view
}

您的下拉列表现在将在您首次生成视图时选择Flightid标识的选项。

请注意。我建议您使用视图模型而不是Tickets数据模型，该模型将包含属性IEnumerable<SelectListItem> Flights和IEnumerable<SelectListItem> StatusList，而不是使用ViewData，以便您的视图使用

@Html.DropDownListFor(m => m.Flightid, Model.Flights)

您还应该考虑重构代码以将SelectLists填充到私有方法中，以便您不重复代码，例如

private void ConfigureViewModel(TicketVM model)
{
    model.Flights = new SelectList(...);
    model.StatusList = new SelectList(...);
}

另请注意，如果SelectList有效，则调用数据库以获取POST方法中的ModelState是浪费资源。你的代码应该是

if (!ModelState.IsValid)
{
     ConfigureViewModel(model); // only necessary if you need to return the view
     return View(model);
}
// save and redirect

附注：不清楚为什么在Flightid视图中确实需要BookTicket的下拉列表。用户已选择航班，为什么您可以选择更改航班？将Flightid渲染为隐藏或只读输入可能更合适，因此将其提交回POST方法。

为下拉列表设置不同的默认值（MVC5）

1 个答案: