![](/img/trans.png)
[英]C# ASP.NET MVC error sharing model between parent and child view using Html.RenderPartial
[英]ASP.Net MVC C# retrieving the last post of a parent child child table
我有一个典型的论坛应用程序,使用嵌套表:
论坛=>主题=>帖子
我正在尝试使用LINQ来填充ViewModel以显示论坛中的帖子的最后一张海报 - 但是,当我运行查询时,我收到错误:
LINQ to Entities does not recognize the method 'centreforum.Models.Post LastOrDefault[Post](System.Collections.Generic.IEnumerable 1[centreforum.Models.Post]) method, and this method cannot be translated into a store expression
我知道它在查询中的这一行:
LastPost = f.Topics.FirstOrDefault().Posts.LastOrDefault().Author
我的控制器是:
public ActionResult Index()
{
var forum = db.Fora.Include(x => x.Topics)
.Select(f => new ForumViewModel
{
ForumId =f.ForumId,
Title=f.Title,
Description=f.Description,
Topics=f.Topics.Count(),
Posts=f.Topics.FirstOrDefault().Posts.Count(),
LastPost = f.Topics.FirstOrDefault().Posts.LastOrDefault().Author
}
).ToList();
return View(forum);
}
我的模特是:
namespace centreforum.Models
{
public class Forum
{
public int ForumId { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public List<Topic> Topics { get; set; }
}
public class Topic
{
public int TopicId { get; set; }
public int ForumId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public string Author { get; set; }
public string DateOfPost { get; set; }
public int Views { get; set; }
public Forum Forum { get; set; }
public List<Post> Posts { get; set; }
}
public class Post
{
public int PostId { get; set; }
public int TopicId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public string Author { get; set; }
public string DateOfPost { get; set; }
public int MyProperty { get; set; }
public Topic Topic { get; set; }
}
}
...而我的ViewModel是:
namespace centreforum.Models
{
public class ForumViewModel
{
public int ForumId { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public int Topics { get; set; }
public int Posts { get; set; }
public string LastPost { get; set; }
}
}
任何人都可以帮我找一个主题中的最后一篇文章,在我的查询中吗?
谢谢,
标记
LastPost = f.Topics.FirstOrDefault().Posts.OrderBy(c => c.CreatedAt).LastOrDefault().Author
我认为,如果您按照给定的标准订购帖子,例如createdat,它应该按预期工作。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.