序列不包含任何元素

本文关键字:元素 何元素 包含任 | 更新日期: 2023-09-27 18:31:15

我正在使用一个类来存储数据,然后使用控制器和视图在使用MVC3的网站上显示数据,但是我遇到了错误,将不胜感激。

类:

public class SampleData : DropCreateDatabaseIfModelChanges<TicketBookingEntities>
    {
        protected override void Seed(TicketBookingEntities context)
        {
            var productions = new List<Production>
            {
                new Production { Name = "Peter Pan" },
                new Production { Name = "Mary Poppins" },
                new Production { Name = "Pirates of the Carribean" },
                new Production { Name = "Joseph" },
                new Production { Name = "Billy Elliot" },
            };
            var directors = new List<Director>
            {
                new Director { Name = "Jason Brown" },
                new Director { Name = "Dan Elish" },
                new Director { Name = "Lee Hall" },
                new Director { Name = "Billie Armstrong" },
                new Director { Name = "Willy Russell" },
            };
            new List<Performance>
            {

                new Performance {Title = "Test", Genre = productions.Single(g => g.Name == "Peter Pan"), Director = directors.Single(a => a.Name == "Jason Brown"), Price = 9.99M, AlbumArtUrl = "/Content/Images/placeholder.gif" },

            }.ForEach(a => context.Performances.Add(a));
        }
    }
}

控制器:

 public ActionResult Browse(string genre)
        {
            var productionModel = storeDB.Productions.Include("Performances")
                .Single(g => g.Name == genre);
            return View(productionModel);
        }

视图:

@model Assignment2.Models.Production
@{
    ViewBag.Title = "Browse";
}
<h2>Browsing Production: @Model.Name</h2>
<ul>
    @foreach (var performance in Model.Performances)
    {
        <li>
            @performance.Title
        </li>
    }
</ul>

错误:

Sequence contains no elements

序列不包含任何元素

你没有列表,你只有一个元素。取出 foreach 循环。

设法解决了这个问题,在控制器上将流派更改为生产