Question

我在View中有一张桌子，上面有一些Car的详细信息。单击“出租”按钮后，将我重定向到另一个视图并在其中显示所选行的数据。使用代码中已有的按钮，我只能在URL中显示该行的详细信息，但不会在页面上显示它们。

这是我的ListOfCars视图：

@model IEnumerable<CarDataAccess.Car>

@{
ViewBag.Title = "List";
Layout = "~/Views/Shared/_Layout.cshtml";
}

<!DOCTYPE html>

<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>ListCars</title>
<script src="~/Scripts/OnClick.js">

</script>
</head>
<body>
@*<p>
        @Html.ActionLink("Create New", "Post")
    </p>*@



<table class="table">

    <tr>
        <th>
            @Html.DisplayNameFor(model => model.model)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.make)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.location)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.avaStart)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.avaEnd)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.price)
        </th>
        <th>

        </th>


    </tr>

    @foreach (var item in Model)
    {
        <tr>

            <td>
                @Html.DisplayFor(modelItem => item.model)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.make)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.location)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.avaStart)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.avaEnd)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.price)
            </td>

            <td>

            <td>@Html.ActionLink("Rent", "Payment", new { id = item.Id })</td>




            </td>




        </tr>

    }

</table>



<div>
    <a href="http://localhost:6664/User/Login">Login</a>
</div>

这是我要在其中显示行的其他视图：

@model IEnumerable<CarDataAccess.Car>


@{
    /**/

    ViewBag.Title = "Payment";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Payment</title>

</head>
<body>
    <table class="paymenttable">

        
    </table>

    

</body>
</html>

控制器代码：

namespace RentCarApplication.Controllers
{
public class HomeController : Controller
{
    BookCarDBEntities db = new BookCarDBEntities();
    public ActionResult Index(int? id)
    {

        ViewBag.Title = "Home Page";

        return View();
    }

    public ActionResult ListCars()
    {
        string username = User.Identity.Name;
        var cars = db.Cars.ToList();

        return View(cars);
    }
 public ActionResult Payment(int id)
    {
       using (BookCarDBEntities entities = new BookCarDBEntities())
        {
            var entity = entities.Cars.FirstOrDefault(c => c.Id == id);

            if (entities != null)
            {
                return View(entity);
            }
            else
            {
                return View("Not Found");
            }

        }






    }
}
}

Answer 1

在控制器操作Payment(int id)中，您将类型CarDataAccess.Car的单个实体传递给视图（代码entities.Cars.FirstOrDefault(c => c.Id == id)中的行从数据库中获取单个实体）。

Payment视图需要一个IEnumerable<CarDataAccess.Car>类型的集合。您可以在视图@model IEnumerable<CarDataAccess.Car>的第一行看到它。将其更改为@model CarDataAccess.Car，看看是否可以解决问题。

将视图更新为此：

@model CarDataAccess.Car 

@{
    /**/

    ViewBag.Title = "Payment";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Payment</title>

    </head>
    <body>
        @* access model properties here *@ 
        <span>@Model.Id</span>


    </body>
</html>

您的控制器中也存在错误。检查Car实体是否不是null，而不是数据库上下文（entities）：

public ActionResult Payment(int id)
{
   using (BookCarDBEntities entities = new BookCarDBEntities())
    {
        var entity = entities.Cars.FirstOrDefault(c => c.Id == id);

        if (entity != null)    // check if entity is null, not entities
        {
            return View(entity);
        }
        else
        {
            return View("Not Found");
        }
    }
}

控制器中也存在另一个问题-您已声明数据库上下文（BookCarDBEntities）的多个实例。最好像在Payment方法中那样，将数据库上下文包装在using语句中。对ListCars方法执行相同操作，然后从控制器顶部删除BookCarDBEntities db = new BookCarDBEntities();。如果将上下文包装在using语句中，则可以确保垃圾收集器正确处理和清除了上下文。

ListCars方法应类似于：

public ActionResult ListCars()
{
    string username = User.Identity.Name;
    var cars = new List<CarDataAccess.Car>();
    using (var db = new BookCarDBEntities())
    {
        cars = db.Cars.ToList();
    } 
    return View(cars);
}

将视图的值显示到另一个视图（MVC）

1 个答案: